103urn:lsid:arphahub.com:pub:77d0745d-c3a1-5248-81de-8cdc02bed84aurn:lsid:zoobank.org:pub:F56F6CF9-7502-4001-A751-35D5F2EF6CA0Arthropod Systematics & PhylogenyASP1863-72211864-8312Senckenberg Gesellschaft für Naturforschung10.3897/asp.84.e201039201039Research ArticleApidaeMolecular systematicsPhylogenyTaxonomyHidden Amazonian diversity: integrative taxonomy reshapes the Meliponaseminigra species complex (Hymenoptera: Apidae: Meliponini)Santos-SilvaJosé Augusto dosdossantossilva.augusto@gmail.comhttps://orcid.org/0000-0003-0612-267712ConceptualizationWriting - original draftFormal analysisInvestigationMethodologyProject administrationNogueiraDavid Silvahttps://orcid.org/0000-0003-2045-019132Writing - review and editingMethodologyValidationFranciniIzaura Bezerrahttps://orcid.org/0000-0002-7730-748724Writing - review and editingData curationInvestigationOliveiraJulio César Carvalho dehttps://orcid.org/0009-0006-6245-520524Writing - review and editingAlvesRogério Marcos de Oliveira25Writing - review and editingCarvalho-ZilseGislene Almeida124Writing - review and editingFunding acquisitionSupervisionOliveiraMarcio Luiz dehttps://orcid.org/0000-0002-3950-108616Writing - review and editingFunding acquisitionSupervisionInstituto Nacional de Pesquisas da Amazônia (INPA), Programa de Pós-Graduação em Entomologia, Manaus, AM, BrazilInstituto Nacional de Pesquisas da Amazônia (INPA), Programa de Pós-Graduação em EntomologiaManausBrazilhttps://ror.org/01xe86309Instituto Federal de Educação, Ciência e Tecnologia do Amazonas (IFAM), São Gabriel da Cachoeira, AM, BrazilInstituto Nacional de Pesquisas da Amazônia (INPA), Coordenação de Biodiversidade, Grupo de Pesquisas em Abelhas (GPA-INPA)ManausBrazilhttps://ror.org/01xe86309Instituto Nacional de Pesquisas da Amazônia (INPA), Coordenação de Biodiversidade, Grupo de Pesquisas em Abelhas (GPA-INPA), Manaus, AM, BrazilInstituto Federal de Educação, Ciência e Tecnologia do Amazonas (IFAM)São Gabriel da CachoeiraBrazilKuapab, Salvador, BA, BrazilInstituto Nacional de Pesquisas da Amazônia (INPA), Programa de Pós-Graduação em Genética, Conservação e Biologia Evolutiva (PPG-GCBEv)ManausBrazilhttps://ror.org/01xe86309Instituto Nacional de Pesquisas da Amazônia (INPA), Programa de Pós-Graduação em Genética, Conservação e Biologia Evolutiva (PPG-GCBEv), Manaus, AM, BrazilUnaffiliatedSalvadorBrazilInstituto Nacional de Biodiversidad (INABIO), División de Entomología, Quito, EcuadorInstituto Nacional de Biodiversidad (INABIO), División de EntomologíaQuitoEcuadorhttps://ror.org/02veev176
Corresponding author: José Augusto dos Santos-Silva (dossantossilva.augusto@gmail.com)
202629092026848158464BB98E9E-E8FE-5F30-9585-129E047E125E2405202607082026José Augusto dos Santos-Silva, David Silva Nogueira, Izaura Bezerra Francini, Julio César Carvalho de Oliveira, Rogério Marcos de Oliveira Alves, Gislene Almeida Carvalho-Zilse, Marcio Luiz de OliveiraThis is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Meliponaseminigra is a polytypic complex of stingless bees broadly distributed throughout the Brazilian Amazon and of major ecological and economic importance due to its role in pollination and meliponiculture. Despite the considerable amount of taxonomic information accumulated over time, the identity and boundaries of its constituent forms have remained uncertain. In this study, we conducted an integrative taxonomic assessment based on specimens deposited in three institutional collections, combining traditional morphological analyses with molecular species-delimitation approaches using COI sequences. Our results provide consistent morphological and molecular evidence supporting the elevation of all currently recognized subspecies of M.seminigra to full species status. Furthermore, we describe two new species, Meliponaatrofulvasp. nov. and Meliponapiceasp. nov., expanding the known diversity within the complex. We also describe, for the first time, three males and two virgin queens previously unknown for already valid taxa. In addition, we present an illustrated worker-based identification key accompanied by detailed morphological diagnoses and an updated distribution map for the group. Together, these findings provide a refined taxonomic framework for the M.seminigra complex and contribute to a better understanding of species diversity, distribution, and evolutionary relationships within one of the most important groups of Neotropical stingless bees.
species delimitationstingless bee taxonomyDNA barcodingmolecular systematicsInstituto Nacional de Pesquisas da Amazônia501100007188https://ror.org/01xe86309http://doi.org/10.13039/501100007188Conselho Nacional de Desenvolvimento Científico e Tecnológico501100003593https://ror.org/03swz6y49http://doi.org/10.13039/501100003593Fundação de Amparo à Pesquisa do Estado do Amazonas501100004916https://ror.org/026d6ma13http://doi.org/10.13039/501100004916Coordenação de Aperfeiçoamento de Pessoal de Nível Superior501100002322https://ror.org/00x0ma614http://doi.org/10.13039/5011000023221. Introduction
Melipona Illiger, 1806 is the most species-rich genus of Meliponini, comprising approximately 70 species restricted to the Neotropical region (Camargo et al. 2023), 40 of them occurring in Brazil, with the majority concentrated in the Amazon basin (Moure and Kerr 1950; Nogueira 2023). In general, species of this genus are robust and densely covered with long, branched hairs of varying colors. They are readily distinguished from other Meliponini by the following combination of characters: wings not or only slightly surpassing the apex of the metasoma; hind wing with well-developed jugal lobe; pterostigma non-convex on the inner surface of the submarginal cell; 9–14 hamuli, rarely 8 or fewer; labial palp setae short and straight (Michener 1990); body generally more densely pubescent than in most other stingless bees; worker ovipositor stylet forming an angular or acute configuration; and male terminalia with a schizogonal capsule and elongated gonocoxites (Schwarz 1932; Snodgrass 1941; Camargo et al. 1967; Camargo 1988; Camargo and Pedro 2008).
The last comprehensive revision of the genus was conducted by Schwarz (1932), and since then numerous taxonomic modifications have been implemented, including the recognition of six subgenera (Camargo et al. 2023). Among these, Melipona (Michmelia) Moure and Kerr, 1950 stands out as the most species-rich subgenus, comprising 38 valid species, 20 of which occur in Brazil, with 16 concentrated in the Amazon basin (Camargo et al. 2023). Since 2013, the Moure Catalogue (Camargo et al. 2023) has informally divided M. (Michmelia) into three species groups, an arrangement maintained by Camargo et al. (2023). However, the morphological characters supporting these groups remain incompletely defined and their limits have not yet been critically evaluated. The Meliponaseminigra complex is included in the informal M.fasciata species group, together with several species that share, among other features, smooth and shiny integument on the discs of the metasomal terga.
The subgenus Michmelia is distinguished from the others by the following set of characters: superior interorbital distance equal to or shorter than the eye length; malar area well developed, its length slightly exceeding or equaling the diameter of the third flagellomere; clypeus convex and matte dorsally on disk, micro-reticulate or evenly micro-punctate, usually lacking widely spaced larger punctures; interocellar distance generally shorter than the ocellorbital distance, and less than twice the diameter of the median ocellus; inner surface of the metatibia with a flat, keirotrichiate zone extending to the non-depressed posterior margin, with the distal angle of the dorsal margin slightly projecting posteriorly; and marginal bands following the ridges, typically narrow, interrupted, or absent on some or all ridges (Moure and Kerr 1950).
Despite its diversity, the species currently placed within this subgenus have not been revised or critically evaluated since their original descriptions, including the four named subspecies of Meliponaseminigra Friese, 1903: (1) Melipona (Michmelia) seminigraabunensis Cockerell, 1912, (2) Melipona (Michmelia) seminigramerrillae Cockerell, 1919, (3) Melipona (Michmelia) seminigrapernigra Moure and Kerr, 1950, and (4) Melipona (Michmelia) seminigraseminigra Friese, 1903. However, a recent study by Francini et al. (2022) demonstrated the genetic differentiation of these geographically separated lineages. Accordingly, in the present study we elevate all these four subspecies to species level based on morphological characteristics, additionally supported by molecular analyses, identify diagnostic morphological characters that allow their separation, describe two new species, provide an identification key, and update the geographic records for all taxa involved.
2. Materials and methods2.1. Taxonomic treatment
We examined 1,517 specimens from the Coleção de Invertebrados of the Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas, Brazil, the Coleção Entomólogica “Prof. J.M.F. Camargo”, Universidade de São Paulo, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP-USP, RPSP, Ribeirão Preto, São Paulo, Brazil), and the entomology collection of the Instituto de Desenvolvimento Sustentável Mamirauá (MAMIRAUÁ, Tefé, Amazonas, Brazil). The photographs and measurements were obtained using a Leica M205A stereomicroscope coupled with a Leica DMC4500 camera and stacked using the software Leica Application Suite v4.10.0 Interactive Measurements, available at the INPA. Montage and figure boards were assembled using Inkscape software. Maps were prepared using QGIS version 3.16. Male genitalia were prepared following the protocol of Nogueira et al. (2022).
Material examined was formatted following the recommendations of Bénichou et al. (2018) for fine-grained taxonomic data presentation in electronic taxonomy publishing, aiming to standardize specimen records and facilitate future indexing and interoperability in biodiversity repositories. Specimen label information was digitized and organized alphabetically by state/province. For RPSP specimens, sequential catalogue numbers linked by a hyphen (“–”) indicate that all numbers within the range are included in the examined material. RPSP specimens are cited using barcode abbreviations, and complete specimen data are available through SpeciesLink using the query format “USP.RPSP + barcode” (e.g., USP.RPSP00005852). Original label information was preserved in cases involving type-material designations. Multiple labels on a single specimen are separated by a slash symbol (“/”). Labels containing repeated information were summarized to optimize space, whereas labels differing only slightly were abbreviated by indicating only the modified information, marked by the arrow symbol (“→”). The symbol “[ ]” indicates incorrectly written or illegible content that could not be confidently interpreted. To facilitate future taxonomic and historical studies, complete verbatim transcriptions of all original labels are provided in the File S1, following the same format adopted for type-material sections.
Paratypes of the new species were deposited in the following institutions: Coleção Entomológica “Prof. J.M.F. Camargo”, Universidade de São Paulo, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP-USP, RPSP, Ribeirão Preto, São Paulo, Brazil); Entomological Collection of the Museu Paraense Emílio Goeldi (MPEG, Belém, Pará, Brazil); and Museu de Zoologia da Universidade de São Paulo (MZUSP, São Paulo, São Paulo, Brazil). The depository of each specimen is indicated by its institutional acronym in the type material designation section for each new species.
We use the following morphological measurements: interocellar distance = distance between the lateral ocelli; ocellorbital distance = distance between the lateral ocellus and the compound eye; clypeocellar distance = distance between the upper portion of the clypeus and the median ocellus; alveolocellar distance = distance between the antennal alveolus (the cuticular rim surrounding the antennal foramen) and the lateral ocellus.
The number of specimens per pin was recorded to clarify the composition of type series. Three mounting conditions were recognized: (i) single mounting, when one specimen is present on a pin; (ii) double mounting, when two specimens are present on the same pin; and (iii) triple mounting, when three specimens are present on the same pin. When multiple specimens were present on a single pin, this was explicitly indicated in the type material description. When no information on the number of specimens per pin was available from labels or collection data, the material was treated as single-mounted by default.
Geographic records were obtained from data of all examined specimens. Records obtained from the literature are indicated in the section “Geographic records”, highlighted in italics, but not included in the map. The morphological terminology follows Camargo and Pedro (2008) and Nogueira et al. (2022). In diagnoses/descriptions, “F” refers to flagellomeres, “S” to sterna, and “T” to terga. In subsequent citations for each species, we update principal taxonomic data following Camargo et al. (2023). We also follow Nogueira et al. (2019), “setae” refers to comparatively rigid, usually simple cuticular structures, whereas “hairs” refers to more flexible structures that are often plumose. Bibliographic entries are separated by “;”. After the year of publication, page numbers referring to the species are provided, and information extracted directly from the referenced work is enclosed in square brackets “[ ]”.
2.2. Genetic data acquisition
The analyses conducted in this study were based on the dataset presented by Francini et al. (2022), who sampled five of the six species examined here. COI sequences were obtained from the vouchers reported in the original publication, and additional specimens were examined using external morphological characters to assess their taxonomic identity. We excluded the morphospecies previously designated as M.s. ssp. 1, as it exhibits intermediate morphological features between two taxa, possibly reflecting management-related admixture. Including such specimens could introduce noise and compromise the accuracy of species-level interpretations.
To compose the outgroup, we selected representatives of four species belonging to Melipona (Michmelia) and one representative of Melipona (Eomelipona) for tree rooting. The complete list of vouchers used in this study is presented in Table SS1.
2.3. Sequence alignment, phylogenetic inference, and molecular species recognition
The 70 COI sequences were aligned using MAFFT (Katoh and Standley 2013) and subsequently trimmed in trimAl (Capella-Gutiérrez et al. 2009) to remove borders, resulting in a final alignment of 526 base pairs. Base composition homogeneity was assessed using a chi-square (χ²) test at a 5% significance level. Identical sequences were then identified and collapsed, yielding a final dataset of 23 unique haplotypes for phylogenetic inference.
Maximum Likelihood (ML) analyses were performed in IQ-TREE v2.0.7 (Minh et al. 2020). Substitution model selection was conducted using ModelFinder (Kalyaanamoorthy et al. 2017), which evaluated 286 candidate models under AIC, AICc, and BIC criteria. Model parameters were optimized during the ML search, and the number of computational threads was automatically assigned by the software. Branch support was assessed using 1,000 ultrafast bootstrap replicates (UFBoot; Hoang et al. 2018) and 1,000 Shimodaira-Hasegawa approximate likelihood-ratio test (SH-aLRT) replicates (Guindon et al. 2010)). The best-scoring ML tree was annotated with both UFBoot and SH-aLRT support values.
An ultrametric COI gene tree for species delimitation analyses was reconstructed in BEAST 2 (Bouckaert et al. 2019). The COI alignment was analysed as a single unpartitioned locus under an uncorrelated lognormal relaxed clock and a Yule tree prior. A secondary calibration of 6.34 ± 0.48 Ma, based on the younger calibration estimate for node 1 of Ramírez et al. (2010), was assigned to the corresponding internal node in our reduced taxon sampling. This node was defined as the most recent common ancestor of the Meliponaseminigra complex, M.flavolineata, M.mondury, M.rufiventris, and M.scutellaris. In the phylogeny of Ramírez et al. (2010), node 1 represents the least-inclusive clade containing M.seminigra and M.captiosa and encompasses the lineages corresponding to the sampled Michmelia representatives included in our dataset. Meliponabicolor, a representative of the subgenus Eomelipona, was included exclusively as an outgroup and was not part of the calibrated node. This was the only secondary calibration used in the analysis. Markov Chain Monte Carlo analyses were run for 20 million generations, with parameters and trees sampled every 5,000 generations. Convergence and effective sample sizes were assessed in Tracer v1.7, and a maximum clade credibility tree was summarized in TreeAnnotator after discarding the first 10% of the sampled trees as burn-in.
2.4. Species delimitation analyses
An integrative species delimitation framework was implemented, combining distance-based, clustering, and tree-based approaches. All analyses were performed in R v.4.4 (R Core Team) using the packages ‘ape’ (Paradis and Schliep 2019), ‘ggtree’ (Yu et al. 2017), and ‘pheatmap’ (Kolde 2025).
The ultrametric tree was imported with read.tree() (ape), and the aligned FASTA sequences were loaded using read.FASTA() (ape). Pairwise genetic distances were computed under the Kimura two-parameter model (K80) using dist.dna(). Four operational delimitation strategies were employed:
Local Minimum (locMin): A histogram of pairwise K80 distances was generated, and local minima were detected using an automated second-derivative-based routine. The first local minimum was used as the threshold for hierarchical clustering (hclust() and cutree()).
GMYC (General Mixed Yule-Coalescent): A simplified GMYC implementation (Fujisawa and Barraclough 2013) was applied using patristic distances (cophenetic()), followed by hierarchical clustering to infer the species boundary transition between Yule and coalescent regimes.
Percent Threshold Method: A conservative threshold corresponding to the 90th percentile of intraspecific distances was calculated and used to define groups through hierarchical clustering.
ASAP (Assemble Species by Automatic Partitioning): The ASAP approach (Puillandre et al. 2021) was applied to the dendrogram of K80 distances, with the number of groups set to k = 5 based on silhouette evaluation.
A heatmap of the genetic distance matrix was produced using pheatmap, employing complete linkage to highlight patterns of genetic structure. Delimitation results were projected onto the ultrametric tree with ggtree, using geom_tiplab() for tip labels and geom_tippoint() with distinct colors to denote the inferred groups. Final figures were edited in Inkscape free software for publication-quality visualization.
3. Results and discussion
Six entities of the Melipona (Michmelia) seminigra species complex were studied, the four former subspecies plus two new species, Meliponaatrofulvasp. nov. and Meliponapiceasp. nov. including the description of the male of the latter. Males of Meliponaabunensis Cockerell, 1912 and Meliponamerrillae Cockerell, 1919 and virgin queens of M.merrillae and Meliponaseminigra Friese, 1903 are described for the first time. All four subspecies were elevated to species level. The six species are diagnosed (Table 1) and discussed below.
Comparative table of diagnostic characters for the Meliponaseminigra species complex (workers).
Worker Meliponaabunensis Cockerell, 1912 from Porto Velho, RO, Brazil. A Body in lateral view and dorsal view; B metasoma in dorsal view; C head in frontal view; D metaleg. Scale: 2.0 mm.
Male Meliponaabunensis Cockerell, 1912 from Purus river, AM, Brazil. A Body in lateral view and dorsal view; B metasoma in dorsal view; C head in frontal view and d. metaleg. Scale: 2.0 mm.
(Fig. 1) Integument in general dark brown to black; terga reddish to brownish (black in M.pernigra and M.piceasp. nov.). Terga and face without yellow spots (present in M.piceasp. nov.). Erect hairs on the suprantennal region, vertex, mesoscutum, and scutellum predominantly dark brown, interspersed with some grayish hairs; occipital region and anterior area of the mesoscutum with whitish hairs (reddish in M.merrillae). Mesopleuron with orangish hairs on the upper half and whitish hairs on the lower half. T1−T5 disc with short, very sparse hairs. Sides of T2–T6 discs with setae as in the other species of the M.seminigra complex (except M.piceasp. nov., which has long, abundant, blackish setae on T5). Setae on the sides of T2–T6 yellowish (blackish in the other species). Metabasitarsus about 2× as long as wide (1.6× in M.atrofulvasp. nov.).
Description, male from Purus River (Amazonas, Brazil).
(Fig. 2) Dimensions: Body length 9.71 mm; forewing length (from tegula base to apex of wing) 8.69 mm; maximum head width 4.08 mm; intertegular distance 2.60 mm; T2 width 3.62 mm. — Coloration: Integument dark brown to black, with yellow spots on the lower paraocular area, median band of the clypeus, malar area, pronotum, and dorso-apical faces of the femora, trochanters and tibiae; sternum light brown; radicle, flagellomeres, labrum, tegula, scutellum and axilla dark yellow to ferruginous. T1 yellow with dark antero-lateral spots; T2−T3 with vestigial posterior premarginal bands, more conspicuous on T2; posterior margins of T1−T6 translucent-rust with a yellowish aspect. Wing membranes hyaline, evenly yellowish; microtrichia and veins yellowish-brown, more strongly pigmented in C and R. — Pubescence: Malar area with very short, fine hairs. Gena with whitish, decumbent hairs interspersed with sparse erect hairs increasing in size toward the mandibular apex. Upper frons with branched, dark-brown, abundant, erect hairs approximately as long as the diameter of F3. Short, decumbent, whitish hairs cover the suprantennal region and lower paraocular area. Clypeus with scarce, simple, decumbent, inconspicuous hairs. Vertex with dark brown hairs up to 2× F3 diameter, with some yellowish hairs laterally on the occipital line. Labrum with abundant, thin, short, yellowish hairs interspersed with longer hairs up to 2.4× that length. Area between antennal sockets with thick, dark setae about as long as the diameter of the scape. Scape with abundant, yellowish, decumbent hairs 0.35× F3 diameter, longer and denser dorsally. Pedicel and flagellomeres with abundant, short, yellowish-brown hairs, especially in sensillar cavities; F1 with basal area almost glabrous and distal 1/3 pubescent as F2−F10. Coxae, trochanters and femora with whitish, branched, long hairs, sparser on inner faces and with some thicker, shorter setae on posterodorsal surfaces of femora. Tibiae with brown, erect, long hairs up to 0.75× tibial width, ventral face with only short, yellowish, decumbent hairs. Tarsi covered by long, thick, brownish setae; metabasitarsus with posterolateral setae up to 1.5× its width and anterolateral setae 0.5× its width. Mesoscutum, scutellum and upper mesopleuron with mixed yellowish and brown, long, erect, branched hairs; mesopleuron setae more whitish, decumbent. Anterior mesoscutum and scutellar margin with hairs longer than the setae on mesoscutal disc, similar in length to vertex hairs. Ventral mesosoma with whitish, branched hairs. T1 disc visibly glabrous. T2−T4 discs with sparse, decumbent, short hairs relative to lateral setae; T5−T6 setae abundant but shorter than lateral setae. Sides of terga with abundant, semi-erect, thick setae, lighter and branched on T1; setae gradually increasing in size length from the anterior to the posterior terga. T3−T4 setae approximately 2× longer in latero-apical half than in latero-basal half. Sterna with yellowish-white hairs, some with curved apices. — Punctation: Sculpture largely faint, integument bright/ shiny, except mesoscutum deeply punctate between piliferous punctures; upper frons finely punctate; clypeus matte-like. — Shape and proportions: Head 1.27× wider than long and 2.62× wider than clypeocellar distance. Eye length 1.06× maximum interorbital distance. Malar area length F3 diameter. Clypeus convex and protuberant, length 0.74× maximum width and 0.94× clypeocellar distance. Mandible length 1.05× clypeocellar distance. Scape length 0.84× alveolocellar distance; scape maximum diameter slightly shorter than F3 diameter. Interocellar distance 1.05× ocellorbital distance and 1.85× median ocellus diameter. Vertex medially with a slight post-ocellar protuberance. Interalveolar distance equal to largest alveolar diameter and 0.72× alveolorbital distance. Alveolocellar distance 2.89× interalveolar distance. Scutellum triangular and protuberant, width 2.76× its maximum length. Forewing length 3× maximum wing width and 2.04× maximum head width. M+Cu bifurcation anterior to cu−a; distal hamuli: 11. Mesotibial length 2× than of mesobasitarsus; metatibia 2.5× longer than wide; metabasitarsus 1.6× longer than wide. Median projection of E7 ogivoid with rounded apex; E8 surface concave with basal recess. Gonostylus long with abundant long setae on posterior third; gonocoxite rectangular, wider than long; genital valve dorsally convex, length exceeding spatha apex; phallus not visible in dorsal or ventral views (Fig. 12A).
Remarks.
This taxon has historically been recognized as the M.seminigra form associated with the western arc of distribution of the complex. Our examination suggests that its morphological limits may be broader than previously assumed, partly due to undersampling in remote areas. This interpretation is also consistent with an unpublished handwritten annotation by J. M. F. Camargo associated with specimens deposited in the INPA collection, in which he noted the possible occurrence of hybrid zones and the presence of individuals combining diagnostic traits of more than one form. We examined 48 specimens from the Purus River that are morphologically consistent with M.abunensis, although they exhibit fuscous metasomal setae rather than the typical coloration. Such cases may represent hybridization, but confirming this hypothesis requires additional approaches and methodologies. Despite the potential for gene flow among forms, we elevate the taxonomic status of M.abunensis based on the genetic evidence presented by Francini et al. (2022), which supports the independent evolutionary identity of the lineages.
Geographic records.
Brazil: Acre (Capixaba, Plácido de Castro, Rio Branco), Amazonas (Tapauá), Mato Grosso (Aripuanã, Cuiabá), Rondônia (Alta Floresta, Ariquemes, Campo Novo, Candeias do Jamari, Costa Marques, Cujubim, Guajará-Mirim, Jarú, Machadinho D’Oeste, Mirante da Serra, Nova Mamoré, Nova União, Ouro Preto, Pimenta Bueno, Porto Velho, Rolim de Moure, São Miguel do Guaporé, Vale do Anari, Vilhena) (Fig. 13).
Worker Meliponamerrillae Cockerell, 1919 from Manaus, AM, Brazil: A Body in lateral view and dorsal view; B metasoma in dorsal view; C head in frontal view and d. metaleg. Scale: 2.0 mm.
Male Meliponamerrillae Cockerell, 1919 from Manaus, AM, Brazil: A Body in lateral view and dorsal view; B metasoma in dorsal view; C head in frontal view and d. metaleg. Scale: 2.0 mm.
Virgin queen Meliponamerrillae Cockerell, 1919 from Manaus, AM, Brazil: A Body in lateral view and dorsal view; B metasoma in dorsal view; C head in frontal view and d. metaleg. Scale: 2.0 mm.
(Fig. 3) Integument in general dark brown to black; terga reddish (black in M.pernigra and M.piceasp. nov.). Terga and face without yellow spots (present in M.piceasp. nov.). Erect hairs on suprantennal region, vertex, mesoscutum, and scutellum predominantly orangish, sometimes with a few black hairs interspersed (predominantly fuscous in the other species; in M.atrofulvasp. nov. with some reddish hairs, but black hairs predominate). Mesopleuron with whitish hairs on the ventral half and orangish hairs on the dorsal half (as in M.atrofulvasp. nov.). T1−T5 disc with short, very sparse hairs. Sides of T2−T6 discs with setae as in the other species of the M.seminigra complex (except M.piceasp. nov., which has long, abundant, blackish setae on T5). Setae on the sides of T2−T6 long and blackish (yellowish in M.abunensis). Metabasitarsus about 2× as long as wide (1.6× in M.atrofulvasp. nov.).
Description, male from Manaus (Amazonas, Brazil).
(Fig. 4) Dimensions: Body length 9.29 mm; forewing length (from tegula base to apex of costal wing) 8.76 mm; maximum head width 4.08 mm; intertegular distance 2.93 mm; T2 width 4.01 mm. — Coloration: Integument dark brown to black, with yellow spots on the lower paraocular area, ventral part of the scape, malar area, pronotum, and dorso-apical faces of the femora, trochanters and tibiae; sterna light brown; labrum and tegula ferruginous. Clypeus dark yellow stained with medium brown. Scutellum, axilla and T1 yellow; T2−T6 uniformly yellowish. Wing membranes hyaline, evenly yellowish; microtrichia and veins yellowish-brown, more strongly pigmented in C and R. — Pubescence: Malar area with very short, fine hairs. Gena with whitish, decumbent hairs interspersed with sparse erect hairs increasing in size toward the mandible. Upper frons with branched, yellowish-white, abundant, erect hairs, some brown hairs on the lower ocellar line as long as the erect hairs of anterior vertex. Short, decumbent, whitish hairs cover the suprantennal region and lower paraocular area. Clypeus with sparse, simple, decumbent, inconspicuous hairs. Vertex with hairs up to 3× F3 diameter, dark brown anteriorly and yellowish on the occipital line. Labrum with abundant, thin, short, yellowish hairs interspersed with longer hairs up to 1.85× their length. Area between antennal sockets with thick, dark setae scape diameter. Scape with abundant, yellowish, decumbent hairs 0.11× F3 diameter, longer and denser dorsally. Pedicel and flagellomeres with abundant, short, yellowish-brown hairs, more conspicuous in sensillar cavities. Coxae, trochanters and femora with whitish, branched, long hairs, sparse on inner faces, with some thicker, smaller hairs on posterodorsal surfaces of femoral. Tibiae with yellowish, erect, long hairs approximately equal to tibial width, ventral face with short, yellowish, decumbent hairs only. Tarsi with long, thick, brownish setae except metabasitarsus where setae reach 1.25× its width posterolaterally and 0.5× its width anterolaterally. Mesoscutum, scutellum and upper mesopleuron with yellowish, long, erect, branched hairs, more whitish and decumbent on the mesopleuron. Anterior mesoscutum and scutellar margin with hairs longer than the setae on mesoscutal disc and similar to vertex hairs. Ventral mesosoma with whitish, branched hairs. T1−T2 discs visibly glabrous. T2−T4 discs with sparse, decumbent, short hairs, nearly absent medially; T5−T6 with abundant setae but reduced relative to lateral setae. Sides of terga with abundant, thick hairs; in T1−T2 lighter and branched, in T3−T6 long, blackish and interspersed setae increasing in size length from the anterior to the posterior terga; in T4 these setae 5× longer in latero-apical half than latero-basal. Sterna with yellowish-white hairs, some with curved apices. — Punctation: Largely faintly sculptured, bright-looking, except mesoscutum deeply punctate between piliferous punctures; suprantennal region finely punctate; clypeus matte-like. — Shape and proportions: Head 1.22× wider than long and 2.72× wider than clypeocellar distance. Eye length 1.06× maximum interorbital distance. Malar area length 0.83× F3 diameter. Clypeus convex, protuberant, length 0.78× maximum width and approximately equal to clypeocellar distance. Mandible length 1.05× clypeocellar distance. Scape length 0.75× alveolocellar distance; scape maximum diameter slightly longer than F3 diameter. Interocellar distance 1.1× ocellorbital distance and 1.91× median ocellus diameter. Vertex medially with a slight post-ocellar protuberance. Interalveolar distance 0.91× alveolar diameter and 0.76× alveolorbital distance. Alveolocellar distance 2.89× interalveolar distance. Scutellum triangular, protuberant, width 2.95× its maximum length. Forewing length 3× maximum wing width and 1.91× head width. M+Cu bifurcation anterior to cu-a; distal hamuli: 12. Mesotibia 2.4× mesobasitarsus; metatibia 2.7× longer than wide; metabasitarsus 2.3× longer than wide. Median projection of E7 ogivoid with rounded apex; E8 surface concave with basal recess. Gonostylus long with abundant long setae on posterior third; gonocoxite rectangular, wider than long; genital valve dorsally convex, length exceeding spathe apex; phallus not visible in dorsal or ventral views (Fig. 12B).
Description, virgin queen from Manaus (Amazonas, Brazil).
(Fig. 5) Dimensions: Body length 8.99 mm; forewing length (from the base of the tegula to the apex of the costal wing) 6.72 mm; maximum head width 3.55 mm; intertegular distance 2.56 mm; T2 width 4.13 mm. — Coloration: Integument predominantly black to brown, with the radicle, base and apex of the scape, tegula, pronotum, scutellum + axilla, and T1 ferruginous; mandible brown; flagellum brownish. Paraocular spot absent. Apices of tibiae and tarsomeres slightly lighter than coxae, trochanters, femora, and basal 2/3 of tibiae. Wing membrane hyaline, evenly yellowish infuscate; microtrichiae and veins yellowish, more strongly pigmented in C and R. Discs of T1−T6 brown. — Pubescence: Malar area glabrous. Gena with yellowish, decumbent hairs interspersed with sparse, yellowish, semierect hairs that increase in size towards the mandibular apex. Upper frons with abundant, light-yellow, semierect, branched hairs, 0.75−1.7× F3 diameter in length. Short, decumbent yellowish hairs covering the entire face except the malar area, sparser on the lower paraocular area and clypeus. Ocellar region lacking conspicuous hairs. Vertex with hairs up to 2.3× F3 diameter, predominantly yellow with some light-brown hairs interspersed in the occipital region. Labrum with thick, long hairs, basal half brown and apical half yellow, reaching up to half of the median clypeal length. Scape with abundant, short, brown pubescence (0.2× F3 diameter). Pedicel and flagellomeres with short, abundant, yellowish-brown hairs; pedicel and F1 with basal glabrous region and distal 1/3 pubescent. Legs with predominantly long, yellow hairs, sparser and thinner on dorsal than ventral faces of the femora; tibiae with shorter and abundant hairs on inner face. Mesosoma with predominantly yellowish, long, branched hairs, longer on anterior mesoscutum; mesopleuron with yellowish-white hairs. T1 disc visibly glabrous, with abundant, predominantly yellowish hairs on lateral margins, longer apically. Discs of T2−T6 covered by thin, short, yellow hairs, with some brown hairs interspersed; pubescence sparser and shorter on T2 and increasing towards the apex of the metasoma. Lateral margins of terga with thicker, longer, and more abundant yellowish hairs, with some brown interspersed. Sterna with yellowish-white hairs, some with curved apices. — Punctation: Sculpture faint, integument shiny. — Shape and proportions: Head 1.2× wider than long and 2.3× wider than clypeocellar distance. Eye length 0.75× maximum interorbital distance. Malar area 2.6× F3 diameter. Clypeus uniformly convex; its length 0.6× maximum width and 1.77× clypeocellar distance. Mandible length approximately equal to clypeocellar distance. Scape length approximately equal to alveolocellar distance; its maximum diameter 1.2× F3 diameter. Vertex concave, with a median postocellar protuberance. Interocellar distance 0.8× ocellorbital distance and 2.3× diameter of median ocellus. Interalveolar distance equal to alveolar maximum diameter and approximately half of the alveolorbital distance. Alveolocellar distance 2.8× interalveolar distance. Scutellum triangular, disc strongly protuberant; its width 1.7× its maximum length. Forewing length 3.1× maximum wing width and 1.9× head width. M+Cu bifurcation anterior to cu-a; distal hamuli: 12. Mesotibia 1.7× mesobasitarsus length. Metatibia 3.1× longer than wide. Metabasitarsus 3.5× longer than wide. Second metatarsomere 3.7× longer than wide.
Remarks.
This species is the subject of the greatest number of ecological and biological studies among the taxa of the complex and is one of the principal species used in meliponiculture (Carvalho-Zilse and Nunes-Silva 2012). Some examined specimens, including those from the Anavilhanas archipelago (in the cities of Novo Airão and Barcelos), and the vicinity of Manaus, display intermediate phenotypes regarding mesosoma pubescence, approaching the condition observed in M.atrofulvasp. nov. Given the widespread moving of colonies for management and intensive multiplication purposes, anthropogenic translocation likely contributes to the occurrence of such intermediates.
Geographic records.
Brazil: Amazonas (Barcelos, Beruri, Careiro, Codajás, Iranduba, Manacapuru, Manaquiri, Manaus, Maraã, Novo Airão, Rio Preto da Eva, Tefé) (Fig. 13).
Workers: BRAZIL: Amazonas • 3 workers; Maués; 6 Apr. 1995; M.V. Garcia leg.; “híbrido? M. s. seminigra × pernigra”; “Moure & Kerr, 1950 Det. Camargo, 1995”; INPA • 1 worker; same data as for preceding except second label; INPA • 1 worker; same data as for preceding except “Amazonas” → “AM”; INPA • 2 workers; same data as for preceding except “Garcia” → “GARCIA”; INPA • 1 worker; Novo Aripuanã, Reserva Soka; 05°15'53"S, 60°07'08"W; 17–25 Aug. 1999; J. Vidal & A.L. Henriques leg.; Malaise trap; INPA • 1 worker; Reserva de Desenvolvimento Sustentável Igapó-Açú, Terra Firme, km 3; 04°43'21.1"S, 61°22'44.5"W; 18–23 Aug. 2013; I.O. Fernandes & A. Somavilla leg.; “Melipona sp.”; Det. M.L. Oliveira, 2016; INPA • 2 workers; Novo Aripuanã, Rio Madeira, Lago Xadá, Comunidade Bela Vista, Ponto 1, margem esquerda; 05°15'39"S, 60°42'32"W; 17–23 Apr.; Xavier-Fo., F.F. Godoi & A.M. Lourido leg.; INPA • 12 workers; RPSP: 00008865–00008867, 00009002–00009010. Maranhão • 1 worker; RPSP: 00008860. Mato Grosso • 1 worker; Paranaíta, UHE Teles Pires; 15 Jul. 2013; Floresta Ombrófila Densa; C.F. Santos leg.; nest 02; RPSP • 1 worker; same data as for preceding except nest 65 and “M. (Michmelia) seminigra pernigra Moure & Kerr”; RPSP. Pará • 14 workers; Mussum, Aveiro; 27 Jan. 1979; Othonyel R.L. Filho leg.; “T-40”; INPA • 1 worker; same data as for preceding except “DR-2”; INPA • 1 worker; Tucuruí, Puraquequara; 4 Aug. 1980; equipe Nunes de Mello leg.; INPA: 5612 • 3 workers; same data as for preceding except INPA: 5619 and 11 Aug. 1980; INPA • 11 workers; same data as for preceding except INPA: 5630; INPA • 1 worker; same data as for preceding except “Melipona seminigra pernigra Moure & Kerr, 1950 Det. Camargo, 2000”; INPA • 4 workers; same data as for preceding except INPA: 5631, 12 Aug. 1980 and “2001”; INPA • 1 worker; same data as for preceding except “Melipona cf. fuscata”; INPA • 110 workers; same data as for preceding except third label; INPA • 1 worker; same data as for preceding except INPA: 5650; INPA • 1 worker; Tucuruí, Remansão; 11 Aug. 1980; equipe Nunes de Mello leg.; INPA: 5619 • 44 workers; Gorotire; 20 Aug.–5 Sep. 1983; Camargo leg.; nest 305c; RPSP • 94 workers; RPSP: 00005096, 00008861–00008864, 00009020–00009100, 00009103–00009107, 00009111, 00009114–00009115. Tocantins • 3 workers; RPSP: 00009108–00009110.
Worker Meliponapernigra Moure and Kerr, 1950 from Feliz Natal, Mato Grosso, Brazil: A Body in lateral and dorsal view; B metasoma in dorsal view; C head in frontal view and d. metaleg. Scale: 2.0 mm.
(Fig. 6) Integument in general dark brown to black; terga black (orangish to brownish in the other species). Terga and face without yellow spots (present in M.piceasp. nov.). Erect hairs on the suprantennal region, vertex, mesoscutum, and scutellum predominantly black, including in the occipital region and the anterior area of the mesoscutum. T1−T5 disc with short, very sparse hairs (as in the other species, except M.piceasp. nov., which has long, abundant blackish setae covering the T5 disc). Sides of T2−T6 discs with abundant, long setae, as in the other species of the M.seminigra complex; setae blackish (yellowish in M.abunensis). Metabasitarsus about 2× as long as wide (1.6× in M.atrofulvasp. nov.).
Remarks.
This species exhibits substantial morphological plasticity, yet its diagnostic characters remain readily recognizable. Specimens from Maués (Amazonas) show features that appear intermediate between M.pernigra and M.piceasp. nov.; however, this region is characterized by intense meliponiculture activity (Carvalho-Zilse and Nunes-Silva 2012), and translocation by beekeepers cannot be excluded as a source of these intermediates. Three specimens from the Xadá lake region (Amazonas state) display intermediate traits distinct from those observed in Maués, which may indicate natural hybridization.
Geographic records.
Brazil: Amazonas (Barreirinha, Borba, Maués, Novo Aripuanã), Maranhão (Imperatriz, Santa Luzia), Mato Grosso (Paranaíta), Pará (Aveiro, Cumaru do Norte, Novo Repartimento, Ourilândia do Norte, Vitória do Xingú), Tocantins (Sítio Novo do Tocantins) (Fig. 13).
Workers: BRAZIL: Amazonas • 1 worker; Itacoatiara; 2 Feb. 1990; M.V.B. Garcia leg.; “M. seminigra seminigra Friese, 1903”; Det. Camargo, 1990; INPA • 5 workers; same data as for preceding except second label; INPA • 1 worker; same data as for preceding except second label: “N° 6”; INPA • 1 worker; same data as for preceding except “AMAZONAS” → “AM”; INPA • 1 worker; Maués; 16 Nov. 1982; F. Peralta leg.; “seminigra [sic]”; INPA • 5 workers; Maués, Meliponário Sr. Claudomiro; 03°24'35.8"S, 57°41'01.3"W; 2 Sep. 2011; Izaura B. Francini leg.; “AMOSTRA 3”; INPA • 3 workers; same data as for preceding except “AMOSTRA PRETA”; INPA • 1 worker; same data as for preceding except “AMOSTRA 1 PRETA”; INPA • 4 workers; same data as for preceding except “Col 1”; INPA • 4 workers; same data as for preceding except “Col 2”; INPA • 6 workers; Boa Vista do Ramos, Represa São Benedito; 02°55'07.9"S, 57°34'18.5"W; 5 Sep. 2011; Izaura B. Francini leg.; “Col 1”; INPA • 2 workers; same data as for preceding except “Col 2”; INPA • 2 workers; same data as for preceding except “Col 3”; INPA • 2 workers; same data as for preceding except “Col 4”; INPA • 2 workers; same data as for preceding except “Col 5”; INPA • 2 workers; same data as for preceding except “Col 6”; INPA • 2 workers; same data as for preceding except “Col 7”; INPA • 2 workers; same data as for preceding except “Col 8”; INPA • 4 workers; Maués; Oct. 1975; Col. Almeida leg.; “Melipona seminigra Friese”; “Col. 2”; INPA • 6 workers; Itacoatiara, Lago Canajari; 17–19 Dec. 1991; F.J. Peralta leg.; INPA • 4 workers; RPSP: 00008937–00008940. Pará • 1 worker; Rio Trombetas, Caetano; 13 Mar. 1986; equipe Apoidea leg.; “M. (Michmelia) seminigra Friese”; Det. Pe. Moure, 1982; INPA: 67 • 1 worker; same data as for preceding except first label; INPA • 1 worker; same data as for preceding except “Eq.” → “Col.” and “M. (Michmelia) seminigra Friese”; INPA • 1 worker; Rio Trombetas, Caetano; 6 Mar. 1986; equipe Apoidea leg.; INPA: 26 • 1 worker; Rio Trombetas, Lago Caetano; 9 Mar. 1986; equipe Apoidea leg.; INPA • 1 worker; same data as for preceding except INPA: 45 and labels: “09-03-86 Eq. APOIDEA”; “RIO TROMBETAS/PA LAGO-CAETANO 09/03/86 Eq. APOIDEA”; “M. seminigra seminigra”; INPA • 12 workers; RPSP: 00008925–00008936. — Virgin queen: BRAZIL: Amazonas • 1 virgin queen; Itacoatiara, Lago Canajari; 17–19 Dec. 1991; F.J. Peralta leg.; INPA.
Worker Meliponaseminigra Friese, 1903 from Rio Trombetas, PA, Brazil: A Body in lateral view and dorsal view; B metasoma in dorsal view; C head in frontal view and d. metaleg. Scale: 2.0 mm.
Virgin queen Meliponaseminigra Friese, 1903 from Itacoatiara, AM, Brazil: A Body in lateral view and dorsal view; B metasoma in dorsal view; C head in frontal view and d. metaleg. Scale: 2.0 mm.
(Fig. 7) Integument in general dark brown to black; terga reddish (black in M.pernigra and M.piceasp. nov.). Terga and face without yellow spots (present in M.piceasp. nov.). Erect hairs on the suprantennal region, vertex, mesoscutum, and scutellum predominantly black, with white hairs on the posterior area of the vertex and anterior area of the mesoscutum (reddish in M.merrillae; grayish in M.abunensis). Mesopleuron with whitish hairs on the ventral half and yellowish hairs on the dorsal half. T1−T5 disc with short, very sparse hairs. Sides of T2−T6 discs with setae as in the other species of the M.seminigra complex (except M.piceasp. nov., which has long, abundant blackish setae on T5). Setae on the sides of T2−T6 long and blackish (yellowish in M.abunensis). Metabasitarsus about 2× as long as wide (1.6× in M.atrofulvasp. nov.).
Description, virgin queen from Itacoatiara (Amazonas, Brazil).
(Fig. 8) Dimensions: Body length 9.36 mm; forewing length (from the base of the tegula to the apex of the costal wing) 7.27 mm; maximum head width 3.56 mm; intertegular distance 2.67 mm; T2 width 4.22 mm. — Coloration: Integument predominantly black, with radicle, base and apex of the scape, tegula, and terga ferruginous; mandibles and flagellum brown. Paraocular spot absent. Apices of tibiae and tarsomeres slightly lighter than coxae, trochanters, femora, and basal 2/3 of tibiae. Wing membrane hyaline, evenly yellowish infuscate; microtrichiae and veins yellowish, more strongly pigmented in C and R. — Pubescence: Malar area glabrous. Gena with yellowish, decumbent hairs interspersed with sparse yellowish, semierect hairs that increase in size toward the mandible. Upper frons with abundant, yellowish-brown, semierect, branched hairs, 0.75–2.3× F3 diameter in length. Short, decumbent, yellowish hairs covering the entire face except the malar area, sparser on the lower paraocular area and clypeus. Ocellar region lacking conspicuous hairs. Vertex with hairs up to 3.1× F3 diameter, light brown with some yellow hairs interspersed in the occipital region. Labrum with thick, long hairs, basal half brown and apical half yellow, up to 0.6× median clypeal length. Scape with abundant, short, yellowish-brown hairs (0.4× F3 diameter). Pedicel and flagellomeres with short, abundant, yellowish-brown hairs; pedicel and F1 with basal glabrous area and distal 1/3 pubescent. Legs with predominantly long yellow hairs, sparse and thinner on the dorsal face of femora; tibiae with shorter and abundant hairs on the inner face. Mesosoma pubescence mixed yellowish and light-brown, long and branched on mesoscutum and scutellum, especially anteriorly; mesopleuron with yellowish-white hairs. T1 disc visibly glabrous, with abundant, predominantly yellowish hairs on lateral margins, longer apically. Discs of T2−T6 with thin, short yellow hairs and some brown hairs interspersed; sparser on T2 and increasing towards T6. Lateral margins of terga with thicker, longer, more abundant yellowish hairs, with some brown interspersed. Sterna with yellowish-white hairs, some with curved apices. — Punctation: Sculpture faint; integument shiny. — Shape and proportions: Head 1.2× wider than long and 3.1× wider than clypeocellar distance. Eye length 0.8× maximum interorbital distance. Malar area 2.9× F3 diameter. Clypeus uniformly convex; its length 0.7× maximum width and 2.4× clypeocellar distance. Mandible length approximately equal to clypeocellar distance. Scape length 1.4× alveolocellar distance; maximum diameter 1.2× F3 diameter. Vertex concave, with median postocellar protuberance. Interocellar distance 0.9× ocellorbital distance and 2.5× diameter of median ocellus. Interalveolar distance 1.1× alveolar maximum diameter and approximately half of alveolorbital distance. Alveolocellar distance 2.8× interalveolar distance. Scutellum triangular, disc strongly protuberant; width 1.9× maximum length. Forewing length 3.1× maximum wing width and 1.9× head width. M+Cu bifurcation anterior to cu-a; distal hamuli: 11. Mesotibia 1.3× mesobasitarsus length. Metatibia 3.4× longer than wide. Metabasitarsus 3.6× longer than wide. Second metatarsomere 3.1× longer than wide.
Remarks.
Meliponaseminigra sensu stricto has long been treated as the typical representative of the complex. In Francini et al. (2022), vouchers identified as M.seminigra correspond to the terminal lineage designated as M.s. ssp. 1, a conclusion we confirmed through examination of the original voucher series. Some specimens are teneral, complicating reliable morphological assessment, while others exhibit traits resembling M.merrillae, which prevented definitive identification. Considering the intense meliponiculture activity in the Manaus region, including managed colonies of M.seminigra, we emphasize the need for comprehensive studies on reproductive interactions and potential introgression or even outbreeding depression among closely related Melipona lineages.
Geographic records.
Brazil: Amazonas (Boa Vista do Ramos, Itacoatiara, Maués), Pará (Oriximiná) (Fig. 13).
Holotype worker: from Barcelos (Amazonas, Brazil) in very good condition. Labels: Brasil, AM, Barcelos, PN Jaú 01°53'15.5"S, 61°41'25.1"W 22-VI-2011 Izaura B. Francini col. Coleta em ninho / 4A. — Paratypes workers (66): Amazonas: 3 (INPA), Brasil, AM, Barcelos, PNJaú 01°53'15.5"S, 61°41'25.1"W 22-VI-2011 Izaura B. Francini col. Coleta em ninho / 4B; 1 (INPA), idem except for the second label: 4A; 6 (INPA); RPSP 846c / Foz do rio Paduari, AM BRASIL 03-05.VIII.1999 02°06'S, 61°13'W Camargo, Pedro, Mazucato / Meliponaseminigra ssp.n. Camargo, MS Det. Camargo, 2000 [double mounting]; 8 (INPA), RPSP 817c / Tapera, Lago Caurés, r. Negro AM Brasil 27-28.VII.1999 01°19'S, 62°11'W Camargo, Pedro, Mazucato / Meliponaseminigra ssp.n. Camargo, MS Det. Camargo, 2000 [double mounting]; 8 (INPA), RPSP 794c / Nazaré, r. Negro, AM Brasil 15-16.VII.1999 00°31'S, 65°04'W Camargo, Pedro, Mazucato / Meliponaseminigra ssp.n. Camargo, MS Det. Camargo, 2000 [double mounting]; 10 (INPA), RPSP 799c / Sumaúma, r. Daraã, AM BRASIL 17-20.VII.1999 00°26'S, 64°45'W Camargo, Pedro, Mazucato / Meliponaseminigra ssp.n. Camargo, MS Det. Camargo, 2000 [double mounting]; 15 (INPA), RPSP 774c / Ilha Grande, Sta. Isabel Rio Negro, AM 11-12.VII.1999 BRASIL 00°26'S, 65°03'W Camargo, Pedro, Mazucato / Meliponaseminigra ssp.n. Camargo, MS Det. Camargo, 2000 [triple mounting]; 1 (INPA), Brasil, AM, Novo Airão Origem colônia =PN Jaú 10-XI-2010 Izaura B. Francini col. Coleta em ninho; 1 (INPA), BRASIL: AMAZONAS RIO NEGRO ANAVILHANAS 22-V-1988 / U. Barbosa Casa Flutuante / Meliponaseminigraatrofulva ssp n Camargo. MS Det. Camargo, 2001; 1 (INPA), BRASIL: AMAZONAS RIO NEGRO PARANA DA ONÇA ANAVILHANAS / 22-V-1988 U. BARBOSA - NO CAMPO; 2 (RPSP); RPSP 846c / Foz do rio Paduari, AM BRASIL 03-05.VIII.1999 02°06'S, 61°13'W Camargo, Pedro, Mazucato / Meliponaseminigra ssp.n. Camargo, MS Det. Camargo, 2000 [double mounting]; 1 (RPSP), Brasil, AM, Novo Airão Origem colônia =PN Jaú 10-XI-2010 Izaura B. Francini col. Coleta em ninho; 2 (RPSP), RPSP 817c / Tapera, Lago Caurés, r. Negro AM Brasil 27-28.VII.1999 01°19'S, 62°11'W Camargo, Pedro, Mazucato / Meliponaseminigra ssp.n. Camargo, MS Det. Camargo, 2000 [double mounting]; 2 (MPEG); RPSP 846c / Foz do rio Paduari, AM BRASIL 03-05.VIII.1999 02°06'S, 61°13'W Camargo, Pedro, Mazucato / Meliponaseminigra ssp.n. Camargo, MS Det. Camargo, 2000 [double mounting]; 1 (MPEG), Brasil, AM, Barcelos, PNJaú 01°53'15.5"S, 61°41'25.1"W 22-VI-2011 Izaura B. Francini col. Coleta em ninho / 4B; 1 (MZUSP), Brasil, AM, Novo Airão Origem colônia =PN Jaú 10-XI-2010 Izaura B. Francini col. Coleta em ninho; 2 (MZUSP), RPSP 794c / Nazaré, r. Negro, AM Brasil 15-16.VII.1999 00°31'S, 65°04'W Camargo, Pedro, Mazucato / Meliponaseminigra ssp.n. Camargo, MS Det. Camargo, 2000 [double mounting].
Holotype worker Meliponaatrofulvasp. nov. from Barcelos, AM, Brazil: A Body in lateral view and dorsal view; B metasoma in dorsal view; C head in frontal view and d. metaleg. Scale: 2.0 mm.
Workers: BRAZIL: Amazonas • 15 workers; Barcelos, Parque Nacional do Jaú; 01°53'15.5"S, 61°41'25.1"W; 22 Jun. 2011; Izaura B. Francini leg.; collected in nest; “4A”; INPA • 5 workers; Barcelos, Parque Nacional do Jaú; 01°53'29.2"S, 61°41'02.5"W; 8 Oct. 2011; Izaura B. Francini leg.; nest in macucuzeiro; “Amostra 5D”; “M. seminigra”; “dout. IBFrancini”; INPA • 5 workers; Barcelos, Parque Nacional do Jaú; 02°58'12.7"S, 57°35'20.0"W; 8 Oct. 2011; Izaura B. Francini leg.; nest in abiorana; “Amostra 5E”; “M. seminigra”; “dout. IBFrancini”; INPA • 5 workers; Barcelos, Parque Nacional do Jaú; 01°53'13.7"S, 61°40'46.1"W; 9 Oct. 2011; Izaura B. Francini leg.; nest in faveira; “Amostra 5F”; “M. seminigra”; “dout. IBFrancini”; INPA • 3 workers; Barcelos, Parque Nacional do Jaú; 01°53'30.5"S, 61°41'53.6"W; 9 Oct. 2011; Izaura B. Francini leg.; nest in macucuzeiro; “Amostra 5G”; “M. seminigra”; “dout. IBFrancini”; INPA • 2 workers; Barcelos, Parque Nacional do Jaú; 01°53'22.7"S, 61°42'47.7"W; 10 Oct. 2011; Izaura B. Francini leg.; nest in taxi; “Amostra 5H”; “M. seminigra”; “dout. IBFrancini”; INPA • 1 worker; Anavilhanas; 31 Aug. 1981; F.J.A. Peralta leg.; INPA • 1 worker; Rio Negro, Anavilhanas; 21–25 Mar. 1988; F.J.A. Peralta leg.; “Melipona seminigra atrofulva ssp. n.”; “Camargo MS Det. Camargo, 2001”; INPA • 1 worker; Rio Negro, Anavilhanas, Lago da Prata, Campo; 21 May 1988; U. Barbosa leg.; INPA • 6 workers; Parque Nacional do Jaú; 19 Mar.–5 Apr. 2003; M.L. Oliveira & J.A. Cunha leg.; avulso; INPA • 1 worker; Parque Nacional do Jaú; 15–27 Jul. 1993; equipe INPA leg.; manual collection; INPA • 2 workers; Parque Nacional do Jaú, Seringalzinho; 01°50'27"S, 61°35'35"W; 29 Aug.–3 Sep. 2004; M.L. Oliveira leg.; INPA • 1 worker; Reserva Extrativista Unini, Rio Unini, Lago Três Bocas; 01°34'56"S, 62°58'28"W; 14–22 Jul. 2004; A. Silva Filho & L. Aquino leg.; mixed mercury + BLB light trap (sheet); INPA • 4 workers; Reserva Extrativista Unini, Rio Unini, Lago Galomãnha, terra firme; 01°37'S, 62°59'W; 13–28 Jul. 2004; M.L. Oliveira, L. Aquino & A. Silva Filho leg.; collected on sweaty clothes; INPA • 1 worker; same data as for preceding except “Em roupa com suor” → “Em coleta manual”; INPA.
Diagnosis, worker.
(Fig. 9) Integument in general dark brown to black; terga reddish (black in M.pernigra and M.piceasp. nov.). Terga and face without yellow spots (present in M.piceasp. nov.). Erect hairs on the suprantennal region, vertex, mesoscutum, and scutellum predominantly black, with some orangish hairs interspersed (almost entirely reddish in M.merrillae). Mesopleuron with whitish hairs on the lower half and orangish hairs on the upper half. T1−T5 disc with short, very sparse hairs. Sides of T2−T6 disc with setae as in the other species of the complex (except M.piceasp. nov., which has long, abundant blackish setae on T5). Setae on the sides of T2−T6 long and blackish (yellowish in M.abunensis). Metabasitarsus about 1.6× as long as wide (2× in the other species).
Description, worker from Barcelos (Amazonas, Brazil).
(Fig. 9) Dimensions: Body length 10.2 mm; forewing length (from tegula base to apex of costal wing) 8.91 mm; maximum head width 4.07 mm; intertegular distance 2.76 mm; T2 width 4.17 mm. — Coloration: Integument dark brown to black. Yellow spots present on the radicle, base of the scape, malar area, basal condyle of the mandible, and pronotum. Paraocular and clypeal spots absent. Pedicel and flagellomeres brownish; tegula and sterna ferruginous. T1−T5 with yellow premarginal bands; discs of T1−T6 reddish to orangish. Wing membranes hyaline, evenly yellowish infuscate; microtrichiae and veins yellowish, more strongly pigmented in C and R. — Pubescence: Malar area with very short, fine hairs. Gena with whitish, decumbent hairs mixed with sparse erect hairs that increase in size towards the mandibular apex. Upper frons with abundant, branched hairs, yellow to brownish, 1−3× F3 diameter in length. Short, decumbent, whitish hairs from upper frons to sparsely covering the lower paraocular area. Ocellar region lacking conspicuous erect pubescence. Vertex with hairs up to 4.3× F3 diameter, predominantly dark brown, with a few yellow hairs in the occipital region. Labrum with short, thin, yellowish hairs, and longer (up to 4.75× as long), wire-like hairs of same coloration. Clypeus with extremely short, inconspicuous pubescence. Interantennal area with thick, dark setae approximately equal in diameter to the scape. Scape with sparse, brownish, decumbent hairs (0.2× F3 diameter). Pedicel and flagellomeres with abundant, short, yellowish-brown hairs; F1 with glabrous basal 2/3 and apical 1/3 pubescent as in F2−F10. Coxae, trochanters, and femora with whitish, branched, long hairs; inner faces of trochanters and femora more sparsely pubescent; posterodorsal femoral area with thicker, shorter setae. Corbicula margin with dark brown to black setae and some white hairs internally; ventral face with fine, yellowish, decumbent hairs. Strigilla length 0.6× maximum corbicula width. Protibia, mesotibia, and tarsi (except metabasitarsus) with thick, dark setae. Tarsomeres with thick, abundant yellow setae internally and black setae externally; base of metabasitarsus with a tuft of yellow hairs. Mesoscutum and scutellum with predominantly orangish, long, branched hairs interspersed with black ones. Mesopleuron with yellowish, branched, decumbent hairs. Ventral mesosoma with whitish, branched hairs. T1−T2 discs nearly glabrous, as in other species of the M.fasciata group; lateral margins with thick, dark setae, largest in apicolateral areas. T1 lateral disc with thinner, lighter hairs than on T2−T6. T3−T6 discs with sparse, short setae relative to lateral areas. Sterna (except S7) with hairs having curved apices, from light brown to yellowish white. — Punctation: Sculpture mostly faint, integument appearing shiny. Mesoscutum distinctly punctate between piliferous punctures. Upper frons and upper portion of clypeus finely punctate and matte. — Shape and proportions: Head 1.25× wider than long, 2× wider than clypeocellar distance. Eye length 0.9× maximum interorbital distance. Malar area 1.25× diameter of F3. Clypeus convex, medioapically protuberant; its length 0.6× maximum width and 0.8× clypeocellar distance. Mandible length clypeocellar and alveolocellar distances; maximum width F3 diameter. Interocellar distance 0.8× ocellorbital distance and 1.9× diameter of median ocellus. Vertex concave, with a median postocellar protuberance. Interalveolar distance equal to alveolar diameter and 0.5× alveolorbital distance. Alveolocellar distance 3.4× interalveolar distance. Scutellum triangular, disc strongly protuberant; width 2.4× its length. Forewing length 3.25× maximum wing width and 2.2× head width. M+Cu bifurcation anterior to cu-a; distal hamuli: 11. Mesotibia length 1.9× mesobasitarsus. Metatibia 2.3× longer than wide, posterodistal corner slightly produced and not forming a right angle. Metabasitarsus 1.8× longer than wide, posterodistally depressed with two lateral projections. Second metatarsomere as long as wide.
Remarks.
Although historically treated as “Melipona seminigra forma do rio Negro” (Camargo 1994) this taxon exhibits a combination of morphological characters that clearly differentiates it from the remaining species of the complex. Francini et al. (2022) treated this lineage as “M. s. ssp. 2” demonstrating that its genetic structure is independent from related forms. Based on this evidence, together with the diagnostic morphological features outlined in the present study, we recognize M.atrofulvasp. nov., as a distinct species. Ramirez et al. (2010) included a terminal designated “M. seminigra atrofulva MP38” in their phylogenetic analysis. Because the name was published without a description, diagnosis, or indication satisfying the requirements for nomenclatural availability, M.seminigraatrofulvaRamírez et al., 2010 is herein regarded as a nomen nudum. Francini et al. (2022) subsequently incorporated the same sequence into their dataset and recovered it within the clade corresponding to “M. s. ssp. 2” The name “atrofulva” originated from an unpublished nomenclatural proposal by J. M. F. Camargo, documented on specimen labels deposited in the INPA and RPSP collections. Based on the correspondence between these labels and the molecular placement of specimen MP38, we associate that terminal with the species described herein as M.atrofulvasp. nov.
Etymology.
This species was one of the unnamed taxa set aside by J.M.F. Camargo in the INPA collection prior to his passing. In homage to him, we retain the epithet atrofulva. The name derives from the Latin ater (black) and fulvus (tawny-yellow), referring to the characteristic bicolored pubescence of the mesosoma in the workers.
Geographic records.
Brazil: Amazonas (Barcelos, Novo Airão, Santa Isabel do Rio Negro) (Fig. 13).
Holotype worker: from Tefé (Amazonas, Brazil) in very good condition. Labels: 5118 / 0149 / Barco Marupiara L. Tefé. Rio Solimões Em 19/10/75 Col - E. Vieira (INPA). — Paratypes workers (82): Amazonas: 28 (INPA), BRASIl. Amazonas. Rio Purus. 15 km a jusante de Camarua. 31.i.1986 Camargo & Mazucato; 2 (INPA), 5118 / 0149 / Barco Marupiara L. Tefé. Rio Solimões Em 19/10/75 Col - E. Vieira; 1 (RPSP), 5118 / 0149 / Barco Marupiara L. Tefé. Rio Solimões Em 19/10/75 Col - E. Vieira; 45 (RPSP), 351c / CAMARUÃ-Rio Purus. AM-Brasil 29 - 1 - 1986 / S8.20,54°25'W-5°46'S Camargo - Mazucato / PARATYPE M.seminigrapicea Camargo & Moure, 198 [7 specimens single mounted, 38 double mounted]; 3 (MPEG), BRASIl. Amazonas. Rio Purus. 15 km a jusante de Camarua. 31.i.1986 Camargo & Mazucato; 3 (MZUSP), BRASIl. Amazonas. Rio Purus. 15 km a jusante de Camarua. 31.i.1986 Camargo & Mazucato. — Paratypes males (26): Amazonas: 1 (INPA), BRASIl. Amazonas. Rio Purus. 15 km a jusante de Camarua. 31.i.1986 Camargo & Mazucato; 25 (RPSP), ♂ / 351c / CAMARUÃ-Rio Purus. AM-Brasil 29 - 1 - 1986 / S8.20,54°25'W-5°46'S Camargo - Mazucato / PARATYPE M.seminigrapicea Camargo & Moure, 198 [21 specimens single mounted, 4 double mounted].
Holotype worker Meliponapiceasp. nov. from Tefé, AM, Brazil: A Body in lateral view and dorsal view; B metasoma in dorsal view; C head in frontal view and d. metaleg. Scale: 2.0 mm.
Paratype male Meliponapiceasp. nov. from Rio Purus, AM, Brazil: A Body in lateral view and dorsal view; B metasoma in dorsal view; C head in frontal view and d. metaleg. Scale: 2.0 mm.
Workers: BRAZIL: Amazonas • 183 workers; Rio Purus, 15 km downstream from Camaruã; 31 Jan. 1986; J.M.F. Camargo & Mazucato leg.; INPA • 1 worker; Reserva de Desenvolvimento Sustentável Mamirauá, Tupã Supé; 16 Jun. 2010; R.C. Farias & J.R. da Silva leg.; Rede Entomológica Dona Sabá; photographed at 08:30 h; “Melipona seminigra pernigra Moure & Kerr, 1950"; Det. F.F. de Oliveira, 2011; MAMIRAUÁ: IDSM CE 1401 • 1 worker; same data as for preceding except MAMIRAUÁ: IDSM CE 1392 • 1 worker; same data as for preceding except MAMIRAUÁ: IDSM CE 1402 • 1 worker; Reserva de Desenvolvimento Sustentável Amanã, Comunidade São João do Ipecaçú, Setor Coraci; 17 Jul. 2010; R.C. Farias & J.R. da Silva leg.; Rede Entomológica Quintal Lindomar; nest in box, “Matá-Matá”; photographed; “Melipona seminigra pernigra Moure & Kerr, 1950”; Det. F.F. de Oliveira, 2011; MAMIRAUÁ: IDSM CE 1610 • 1 worker; Reserva de Desenvolvimento Sustentável Mamirauá, Piraré; 17 Jun. 2010; Rede Entomológica Flor Ruderal; “Melipona seminigra pernigra Moure & Kerr, 1950”; Det. F.F. de Oliveira, 2011; MAMIRAUÁ: IDSM CE 1416.
Diagnosis, worker.
(Fig. 10) Integument in general dark brown to black; terga black (reddish in M.abunensis, M.atrofulvasp. nov., M.merrillae, and M.seminigra). T1−T4 usually with premarginal yellow bands. Clypeus usually with a vestigial but visible median yellow band (absent in the other species). Erect hairs on the suprantennal region, vertex, mesoscutum, and scutellum predominantly yellowish, with dark brownish hairs on the anterior area of the vertex (reddish in M.merrillae; blackish in M.abunensis, M.seminigra, and M.pernigra). Mesopleuron with yellowish hairs. T1−T4 disc with short, sparse hairs; T5 disc with long, abundant blackish setae, almost as long as those on the sides of the disc. Sides of T2−T6 with setae as in the other species of the complex. Setae on the sides of T2−T6 long and blackish (yellowish in M.abunensis). Metabasitarsus about 2× as long as wide (1.6× in M.atrofulvasp. nov.).
Description, holotype worker from Tefé (Amazonas, Brazil).
(Fig. 10) Dimensions: Body length 9.71 mm; forewing length 8.81 mm; maximum head width 4.08 mm; intertegular distance 2.84 mm; T2 width 3.95 mm. — Coloration: Integument dark brown to black. Yellow spots present on: median vestigial band of the clypeus, radicle, base and apex of scape, pronotum, axilla, and scutellum. Paraocular spot absent. Tegula ferruginous; scutellum and sterna brownish. T1−T5 with yellow posterior marginal bands. Wing membranes hyaline, evenly yellowish infuscate; veins and microtrichiae yellowish, darker in C and R. — Pubescence: Malar area with very short, fine hairs. Gena with whitish, decumbent hairs mixed with sparse erect hairs increasing in length towards the mandibular apex. Upper frons with abundant, branched, erect hairs, yellow to brownish, 1−2× F3 diameter. Short, decumbent hairs from upper frons to lower ocular area, delimiting the upper clypeal margin. Ocellar line without conspicuous pubescence. Vertex with hairs up to 3.3× F3 diameter, brown anteriorly and yellow in occipital region. Clypeus surface with extremely short, inconspicuous hairs. Labrum with abundant short yellowish hairs, and longer ones (1.5× as long) intermixed. Interantennal area with thick, dark setae nearly as wide as the scape. Scape with abundant yellowish decumbent hairs (0.2× F3 diameter), and sparse dark brown erect setae, especially dorsally. Pedicel and flagellomeres with abundant short yellowish-brown hairs; F1 with basal glabrous 2/3 and apical 1/3 pubescent as in F2−F10. Coxae, trochanters, and femora with long, branched, whitish hairs, sparse on inner faces; posterodorsal area of femur with thick, short setae. Protibia, mesotibia, and tarsi (except metabasitarsus) with thick dark setae. Corbicula margin with dark brown to black setae and some inner white hairs; ventral area with fine, yellowish decumbent hairs. Strigilla length 0.7× maximum corbicula width. Metabasitarsus externally with sparse hairs. Tarsomeres with abundant yellow setae internally and black setae externally; base of metabasitarsus with tuft of yellow hairs. Mesoscutum, scutellum, and mesopleuron with predominantly yellowish, long, branched hairs; mesoscutum and scutellum with a few brown setae interspersed. Small tuft of pale brown to yellow setae posteroventrally to forewing insertion. Ventral mesosoma with whitish hairs. T1−T2 discs almost glabrous as in other M.fasciata group species. Thick, dark lateral setae on discs, longer apicolaterally. T1 lateral disc with lighter, thinner hairs than T2−T6. T3−T4 discs with sparse, short hairs; T5 with abundant, clearly visible long setae (half-length of lateral setae). Sterna (except S7) with hairs with curved apices, light brown to yellowish white. — Punctation: Integument mostly faintly sculptured, shiny; mesoscutum distinctly punctate between piliferous punctures; upper frons and upper clypeus finely punctate and matte. — Shape and proportions: Head 1.22× wider than long and 2.48× wider than clypeocellar distance. Eye length 0.92× maximum interorbital distance. F3 diameter 1.25× length of malar area. Clypeus convex and medioapically protuberant; length 0.59× width and 0.76× clypeocellar distance. Mandible length clypeocellar distance. Scape length alveolocellar distance; maximum diameter 1.1× F3 diameter. Interocellar distance 0.39× ocellorbital distance and 2.23× median ocellus diameter. Vertex concave with postocellar median protuberance. Interalveolar distance 1.37× alveolar diameter and 0.58× alveolorbital distance. Alveolocellar distance 2.98× interalveolar distance. Scutellum triangular, strongly protuberant; width 2.76× its length. Forewing 3.47× its maximum width and 2.16× head width. M+Cu bifurcation anterior to cu-a; distal hamuli: 13. Corbicula 1.44× longer than wide, posterodistal corner slightly produced, not forming right angle. Metabasitarsus 1.39× longer than wide, posterodistally depressed with two lateral projections. Second metatarsomere 1.39× longer than wide.
Description, paratype male from Rio Purus (Amazonas, Brazil).
(Fig. 11) Dimensions: Body length 9.59 mm; forewing length (from tegula base to apex of costal wing) 8.69 mm; maximum head width 4.08 mm; intertegular distance 2.60 mm; T2 width 3.62 mm. — Coloration: Integument black, with yellow spots on the lower paraocular area, median band of the clypeus, malar area, pronotum, and dorso-apical face of the trochanters; radicle, basal scape area, tegula, and anterior and lateral areas of T1 ferruginous; sternum brownish. Paraocular spot strongly yellow, extending to the lower clypeal edge and connecting to clypeal spots; clypeal spots very conspicuous, wider in the upper than lower half and linked to a conspicuous supraclypeal yellow spot. Circular ferruginous spot-on apical part of legs. T1−T5 with conspicuous yellow premarginal bands. Wing membranes hyaline, evenly yellowish; microtrichia and veins yellowish-brown, more strongly pigmented in C and R. — Pubescence: Malar area with very short, fine hairs. Gena with whitish, decumbent hairs interspersed with sparse erect hairs increasing toward mandible. Upper frons with branched, dark brown, abundant, erect hairs approximately the diameter of F3. Short, decumbent, whitish pubescence from suprantennal region to lower paraocular area, shorter in lower paraocular than in malar area. Vertex with hairs up to 2.5× F3 diameter, dark brown anteriorly and bright yellow in occipital region. Labrum with thin, short, yellowish hairs; clypeus surface with very short, inconspicuous hairs. Area between antennal sockets with thick, dark setae about scape diameter. Scape with abundant, yellowish, decumbent hairs 0.2× F3 diameter, denser dorsally and interspersed with sparse dark erect setae. Pedicel and flagellomeres with abundant, short, yellowish-brown hairs, more visible in sensillar cavities. Coxae, trochanters and femora with whitish, branched, long hairs, sparse on inner faces, with thicker, smaller hairs on posterodorsal femora; ventral tibial face with short, yellowish, decumbent hairs, other tibial faces with long, erect hairs. Tarsi with long, thick, brownish setae except metabasitarsus where posterolateral setae reach 1.5× its width and anterolateral setae 0.5× its width. Mesoscutum, scutellum and upper mesopleuron with erect, long, branched hairs predominantly yellowish, interspersed with fuscous hairs and a tuft of darker hairs below forewing insertion. Hairs on anterior mesoscutum and scutellar margin longer than vertex hairs. Lower mesopleuron and ventral mesosoma with yellowish hairs. T1−T2 disc virtually glabrous. T2−T4 disc with sparse, decumbent, short brownish setae; T5−T6 with abundant but short setae relative to sides. Sides of terga with abundant, thick, brownish hairs, lighter and erect on T1; setae gradually increase toward metasomal apex. T3−T4 setae 2× longer in latero-apical than latero-basal region. Sterna with yellowish-white hairs, some with curved apices. — Punctation: Largely faintly sculptured, bright-looking, except mesoscutum deeply punctate between piliferous punctures; suprantennal region finely punctate; clypeus matte-like. — Shape and proportions: Head 1.19× wider than long and 3.55× wider than clypeocellar distance. Eye length 1.05× maximum interorbital distance. F3 diameter 1.32× malar length. Clypeus convex and protuberant, length 0.81× maximum width and 1.35× clypeocellar distance. Mandible length 1.3× clypeocellar distance. Scape length 0.82× alveolocellar distance; scape maximum diameter slightly smaller than F3 diameter. Interocellar distance 1.05× ocellorbital distance and 1.85× median ocellus diameter. Vertex with slight post-ocellar protuberance. Interalveolar distance 0.74× alveolar diameter and 0.83× alveolorbital distance. Alveolocellar distance 3.03× interalveolar distance. Scutellum triangular, protuberant, width 2× its maximum length. Forewing length 3× maximum wing width and 1.88× head width. Mesotibia 1.8× mesobasitarsus; metatibia 2.9× longer than wide; metabasitarsus 1.6× longer than wide. E7 median projection ogivoid with rounded apex; E8 surface concave with basal recess. Gonostylus long with abundant setae on posterior third; gonocoxite rectangular, wider than long; genital valve dorsally convex, length exceeding spathe apex; phallus not visible in dorsal or ventral views (Fig. 12C).
Remarks.
Camargo (1994) first recognized this form as “Melipona seminigra forma de Tefé,” noting its distinctiveness within the complex. M.piceasp. nov. is easily separable from congeners by its conspicuous yellow tergal bands and characteristic pubescence pattern. In the Purus River series collected by J. M. F. Camargo and M. Mazucato, the pre-marginal bands are more translucent and less conspicuous, likely because the specimens were taken directly from nests and may not have been fully pigmented. Although M.piceasp. nov. was not included in the analyses of Francini et al. (2022), its placement within the M.seminigra complex is supported by morphological traits such as the pattern of setae on the tergal discs. It shows partial resemblance to M.lateralis, M.fuscopilosa, and M.eburnea due to the presence of yellow pre-marginal bands; however, the glossy integument of terga disc and distribution of erect setae on sides of terga disc leave no doubt about its affinity to the M.seminigra group. A robust phylogenetic analysis of the M.fasciata group will be necessary to precisely resolve its relationships (in preparation).
Etymology.
This species was likewise among the unnamed forms separated by J. M. F. Camargo in the INPA collection before his death. In recognition to his contribution and to preserve his intended nomenclature, we maintain the epithet picea. The name alludes to the dark, pitch-like coloration of the integument (from Latin piceus, meaning “pitch-black”).
3.2. Key for identification of <italic><tp:taxon-name><tp:taxon-name-part taxon-name-part-type="genus" reg="Melipona">Melipona</tp:taxon-name-part> <tp:taxon-name-part taxon-name-part-type="species" reg="seminigra">seminigra</tp:taxon-name-part></tp:taxon-name></italic> species complex (workers)
1
Terga T2–T4 entirely black, with or without yellow premarginal bands (Figs 6B, 10B)
2
1’
Terga T2–T4 predominantly orange to reddish, with or without yellow premarginal bands (Figs 1B, 3B, 7B, 9B)
3
2
Pubescence of mesosoma predominantly yellowish (Fig. 10A); setae on the disc of T5 nearly as long as those along its lateral margins; T1–T5 with conspicuous yellow premarginal bands (Fig. 10C). Western Amazonia, centered in the Tefé region and associated with the Napo area of endemism
Meliponapicea sp. nov.
2’
Pubescence of mesosoma predominantly black (Fig. 6A); disc of T5 nearly glabrous, bearing only short, sparse setae; T1–T5 without yellow premarginal bands (Fig. 6C). Distributed from the Tapajós basin to northwestern Maranhão, across the Tapajós-Xingu-Tocantins interfluves
Meliponapernigra Moure and Kerr
3
Lateral setae on the discs of T1–T5 yellowish to orange (Fig. 1B). Southwestern Amazonia, primarily in the Aripuanã-Madeira interfluve in Rondônia
Meliponaabunensis Cockerell
3’
Lateral setae on the discs of T1–T5 dark brown to black (Figs 3B, 7B, 9B)
4
4
Erect setae on the vertex, mesoscutum, and scutellum predominantly orange, occasionally with a few interspersed dark setae (Fig. 3A, C). Widely distributed in central Amazonia, centered around Manaus and mainly associated with the Inambari area of endemism
Meliponamerrillae Cockerell
4’
Erect setae on the vertex, mesoscutum, and scutellum predominantly black, occasionally with a few interspersed orange or pale setae (Figs 7A, 7C, 9A, 9C)
5
5
Erect setae on the vertex black anteriorly and reddish on the occipital region; mesoscutum and scutellum with orange setae intermixed with black pubescence (Fig. 9A, C); metabasitarsus approximately 1.6× as long as wide (Fig. 9D). Restricted to the Negro-Branco interfluve, corresponding to the Jaú area of endemism
Meliponaatrofulva sp. nov.
5’
Erect setae on the vertex black anteriorly and whitish on the occipital region; pubescence of mesoscutum and scutellum predominantly black, with a few whitish setae on the anterior portion of the mesoscutum (Fig. 7A, C); metabasitarsus approximately 2.0× as long as wide (Fig. 7D). Restricted to the lower Amazon region, primarily between the Madeira-Tapajós and Tapajós-Trombetas interfluves, in the Guiana area of endemism
Meliponaseminigra Friese
3.3. Species delimitation and genetic distance analysis
The species delimitation analysis employing four independent methods (locMin, GMYC, percent, ASAP) revealed remarkable concordance in identifying five distinct specific units within the complex (Fig. 14). The genetic distance matrix, calculated under the K80 model, exhibited clear patterns of genetic structuring that strongly support this delimitation (Fig. 15). When considered alongside morphological hypotheses, these results justify elevating the taxonomic status of these units rather than treating them as geographical races (lineages considered here), as originally proposed by Camargo (1994).
S7 in dorsal and lateral view, S8 in dorsal and lateral view, genital capsule in dorsal (left) and ventral (right) view, genital capsule valve in lateral view. AMeliponaabunensis; BMeliponamerrillae; CMeliponapiceasp. nov. Scale: 1.0 mm.
Distribution map based on occurrence records extracted from specimen labels, including all previously recognized and newly described species within the Meliponaseminigra complex. Amazonian areas of endemism are overlaid following Cracraft (1985), Silva et al. (2002), Naka (2011), Borges and Silva (2012), and Ribas et al. (2025). National boundaries are indicated by white outlines, and country abbreviations (CO = Colombia, BR = Brazil, GY = Guyana, GF = French Guiana, SR = Suriname, VE = Venezuela, PE = Peru, BO = Bolivia). The map was produced in QGIS using the SIRGAS 2000 geographic coordinate system (EPSG:4674).
Maximum-likelihood phylogenetic tree inferred without the outgroup, based on 1,000 bootstrap pseudoreplicates, displayed alongside the clusters recovered by the four species-delimitation methods applied in this study. An additional column indicates the correspondence between the recovered genetic clusters and the morphologically defined species. Bootstrap support values are shown at the nodes.
Heatmap depicting pairwise genetic distances estimated under the Kimura 2-parameter (K80) model. Warmer colors indicate higher, cooler colors indicate lower sequence divergence. The matrix summarizes intra- and interspecific variation among all sampled individuals and supports patterns of divergence discussed in the text.
https://binary.pensoft.net/fig/1793014
Measurements (in mm) of selected males, workers, and virgin queens described and studied herein. Meliponaabunensis – male from Porto Velho, AM, Brazil; Meliponamerrillae – male and virgin queen from Manaus, AM, Brazil; Meliponaseminigra – virgin queen from Itacoatiara, AM, Brazil; Meliponapiceasp. nov. – holotype worker from Tefé, AM, Brazil and paratype male from Rio Purus, AM, Brazil; Meliponaatrofulvasp. nov. – holotype worker from Barcelos, AM, Brazil. Values are not intended for direct morphometric comparison among castes, but to document diagnostic proportions and size ranges.
Measurements (mm)
M.abunensis Cockerell, 1912
M.merrillae Cockerell, 1919
M.seminigra Friese, 1903
M.picea sp. nov.
M.atrofulva sp. nov.
Male from Porto Velho (RO, Brazil)
Male from Manaus (AM, Brasil)
Virgin queen from Manaus (AM, Brazil)
Virgin queen from Itacoatiara (AM, Brazil)
Holotype worker
Paratype male
Holotype worker
Total body length
9.25
9.26
8.99
9.36
9.71
9.59
10.2
Max head width
3.82
4.08
3.55
3.56
4.08
4.08
4.07
Head length
3.01
3.33
2.93
2.97
3.35
3.42
3.24
Eye length
2.30
2.50
1.93
1.94
2.50
2.52
2.38
Max interorbital distance
2.16
2.36
2.56
2.52
2.68
2.38
2.65
Middle ocellus diameter
0.35
0.33
0.25
0.25
0.26
0.34
0.30
Distance between middle and lateral ocellus
0.12
0.15
0.17
0.22
0.17
0.16
0.15
Interocelar distance
0.66
0.63
0.58
0.63
0.58
0.63
0.59
Ocelorbital distance
0.52
0.57
0.69
0.66
0.68
0.60
0.67
Interalveolar distance
0.37
0.39
0.40
0.41
0.44
0.38
0.38
Alveolorbital distance
0.51
0.51
0.75
0.69
0.75
0.46
0.73
Alveolocer distance
1.07
1.15
1.14
1.16
1.31
1.15
1.28
Alveolus diameter
0.37
0.43
0.4
0.39
0.32
0.51
0.39
Clypeus length
1.37
1.5
1.17
1.24
1.26
1.55
1.30
Max clypeus width
1.86
1.92
1.87
1.77
2.12
1.91
2.02
Clypeus width in the tentorial pits
1.10
1.16
1.20
1.17
1.13
1.16
1.18
Clypeocelar distance
1.46
1.50
1.49
1.52
1.66
1.15
1.63
Malar area length
0.22
0.20
0.47
0.49
0.25
0.19
0.26
Scape length
0.90
1.12
1.23
1.64
1.41
0.94
1.38
Scape diameter
0.23
0.26
0.21
0.21
0.22
0.23
0.22
F3 diameter
0.22
0.24
0.18
0.17
0.20
0.25
0.20
F1 length
0.31
0.23
0.30
0.32
0.29
0.25
0.30
F2 length
0.31
0.37
0.34
0.35
0.31
0.24
0.28
F3 length
0.31
0.34
0.35
0.40
0.30
0.24
0.30
Mandible length
1.54
1.60
1.47
1.52
1.73
1.49
1.89
Forewing length
7.32
7.78
6.01
6.63
8.00
7.68
8.03
Forewing + tegula length
7.79
8.76
6.72
7.27
8.81
8.69
8.91
Forewing width
2.08
2.50
2.08
2.36
2.54
2.57
2.74
Mesoscutum width
2.99
2.93
2.56
2.67
2.84
2.6
2.76
Mesoscutum length
2.38
2.68
1.79
1.83
2.72
2.79
2.76
Scutellum + Axilla width
2.17
2.41
1.94
2.17
2.10
2.18
2.43
Scutellum length
1.14
1.16
1.12
1.16
0.76
1.09
1.03
Mesotibia length
1.91
2.16
2.01
1.91
1.89
1.90
2.29
Mesobasitarsus length
1.43
0.89
1.21
1.43
1.47
1.08
1.20
Metatibia length
2.51
2.79
2.56
2.92
2.46
2.50
3.12
Max metatibia width
1.01
1.02
0.82
0.86
1.71
0.86
1.35
Metabasitarsus length
1.34
1.53
1.60
1.73
1.94
1.20
1.63
Metabasitarsus width
0.66
0.65
0.46
0.48
1.21
0.74
0.90
T2 width
4.09
4.01
4.13
4.22
3.95
3.59
4.17
The distance matrix revealed a clear separation among the five specific groups, with intraspecific distances substantially lower than interspecific distances. Intraspecific distances ranged from 0.0% to 0.9% (Fig. 15), indicating high genetic homogeneity within each species, distinct from patterns observed in closely related groups (Batalha-Filho et al. 2010; Miranda et al. 2012, 2016). This low genetic variability may be partially influenced by the sampling strategy employed by Francini et al. (2022), which relied predominantly on colonies maintained under meliponiculture conditions. However, it is important to note that part of the sampling, particularly in Rondônia and in Parque Nacional do Jaú, also included individuals obtained from natural nests, such as those collected during bee rescue operations and from colonies in the wild. Despite this, the reduced heterogeneity, or pronounced homogeneity, observed in some species may still reflect the geographically restricted sampling conducted by Francini et al. (2022), particularly in taxa such as M.merrillae and M.atrofulvasp. nov. Additionally, sampling from meliponiculture operations raises the possibility that genealogically related lineages were inadvertently represented, thereby underestimating true intraspecific diversity.
Future studies should therefore expand geographic and population-level sampling, explicitly incorporating both managed colonies (meliponaries) and wild nests, to properly evaluate intraspecific genetic structure and provide a more robust basis for reconstructing the demographic history of each species within its biogeographical context. By contrast, interspecific distances were considerably higher, ranging from 1.5% to 2.9%, reflecting pronounced genetic divergence among taxa (Fig. 15).
Meliponaabunensis displayed exceptional genetic cohesion, with minimal intraspecific distances and multiple genetically identical individuals. Likewise, M.merrillae, M.pernigra, and M.atrofulvasp. nov. exhibited complete genetic homogeneity (distance = 0.000) within their groups. M.abunensis and M.seminigra showed slight internal structure, with intraspecific distances of 0.0−0.3%, suggesting potential population substructuring.
3.4. Phylogenetic relationships and congruence among methods
The delimitation methods applied (locMin, GMYC, percent, ASAP) exhibited considerable congruence in recovering the five specific groups, with GMYC being the only method that fully recovered all morphologically defined species (Fig. 14). This is likely because GMYC operates on an ultrametric tree, incorporating branching patterns and timing, whereas the other methods rely solely on genetic distances.
Genetic distances among taxa indicated that M.atrofulvasp. nov. and M.merrillae share the smallest interspecific distance (0.007%), suggesting a comparatively closer relationship. M.pernigra exhibited the highest genetic distances relative to the other taxa (2.1−2.9%), positioning it as the most divergent lineage within the complex. This pronounced differentiation is also consistent with its geographical distribution, which is largely associated with the eastern Amazon and the Tapajós-Xingu region, whereas the remaining species are concentrated farther west or north in distinct Amazonian interfluves. The occupation of geographically separated biogeographical units, potentially isolated by major river systems and unsuitable intervening areas, may have contributed to the differentiation of M.pernigra. However, testing this hypothesis will require broader geographical sampling and explicit phylogeographical analyses. Based on morphological evidence, we suspect that M.piceasp. nov., absent from the dataset, may be closely related to M.pernigra.
The combined results provide robust genetic support for recognizing five species that are putatively distinct biologically, corroborating traditional taxonomic boundaries based on morphological traits. The absence of intermediate values or overlap between intra- and interspecific distances reinforces the genetic distinctiveness of the identified species.
The integration of the maximum-likelihood phylogeny with delimitation results demonstrated strong correspondence between genetic clusters and phylogenetic structuring, further supporting the consistency of the observed patterns. The genetic distance matrix independently confirmed the formation of well-defined clusters that correspond to each species.
The delimitation approaches were essential for interpreting our results, given that nodal support values (UFBoot and SH-aLRT) were below 90 in some instances, likely due to the limited number of base pairs in the fragment selected by Francini et al. (2022). Future species delimitation studies would benefit from markers with greater genomic coverage and, when feasible, multilocus and NGS-based approaches.
3.5. Biogeographic patterns
The geographic distribution of species within the M.seminigra complex reveals a spatial structure broadly consistent with diversification associated with Amazonian interfluvial regions, a pattern extensively documented in several Neotropical taxa (Cracraft 1985; Silva et al. 2002; Naka 2011; Borges and Silva 2012; Ribas et al. 2025), but still poorly explored in stingless bees. Major Amazonian rivers have long been proposed as ecological and historical barriers limiting dispersal and gene flow, thereby promoting population isolation and lineage diversification. In this context, the observed distributional patterns within the M.seminigra complex suggest a potential role of the Amazonian hydrographic network in shaping species limits and geographic structure.
Early insights into the geographic differentiation of these forms were provided by Camargo (1994) based on extensive field expeditions. Here, we expand upon those observations by explicitly associating species-level distributions with recognized Amazonian areas of endemism. Below, we discuss each species individually, highlighting patterns of spatial restriction, interfluvial association, and marginal occurrences, and their implications for the historical biogeography of the complex:
Meliponaseminigra occurs primarily in the lower Amazon region, with records concentrated between Maués and the middle to lower course of the Trombetas River. Although its western and eastern distributional limits remain incompletely documented, available data indicate that the species is largely restricted to the Guiana area of endemism, being apparently confined between the Madeira-Tapajós and Tapajós-Trombetas interfluves, both recognized as distinct biogeographic units. The westernmost record examined here is from Itacoatiara, located east of the mouth of the Madeira River along the Amazon main channel. Given its marginal position relative to the core distribution of the species, this occurrence is more plausibly interpreted as the result of recent nest translocation associated with intensive meliponiculture in the region, rather than evidence of a natural population.
Meliponamerrillae is widely distributed in central Amazonia, with most records concentrated in the Manaus region. Its range extends southwards to Paricatuba, in the lower Purus basin, and westwards to the Camanaú river (Amazonas State). Although the northern limits of its distribution remain poorly defined, we recorded individuals east of the confluence of the Branco and Negro rivers. In terms of Amazonian areas of endemism, M.merrillae is primarily associated with the Inambari region, with additional occurrences in the Guiana area and marginal records along interfluvial boundaries. Notably, reports of intergradation with M.atrofulvasp. nov. suggest the presence of a secondary contact zone, characterized by a gradual transition of phenotypes rather than abrupt species boundaries, likely reflecting historical connectivity or recent dispersal across adjacent interfluves.
Meliponaabunensis is predominantly distributed in southwestern Amazonia, with most records concentrated in Rondônia, particularly within the Aripuanã-Madeira interfluve. Its range extends westwards to the Ipixuna and Jacaré-Purus rivers, and southwestwards to Ivon, along the Beni River in Bolivia; additionally, we recorded a single, markedly disjunct occurrence in the Juruá-Humaitá interfluve. Towards the east, the species approaches the Tapajós basin, although no core populations are known east of this region. From a biogeographic perspective, M.abunensis is mainly associated with the Rondônia and Inambari areas of endemism. Notably, its distribution overlaps marginally with that of closely related species, forming transition zones characterized by intermediate phenotypes. In the lower Purus-Paricatuba region, M.abunensis comes into contact with M.merrillae, whereas in the upper Purus basin it meets M.piceasp. nov. In both cases, the presence of intermediate forms is best interpreted as evidence of secondary contact and limited introgression along interfluvial boundaries.
Meliponapernigra exhibits the broadest geographic range within the M.seminigra complex. It is widely distributed from the Tapajós basin eastwards to northwestern Maranhão, encompassing large portions of the middle and lower Tocantins and Xingu basins. In contrast to other members of the complex, this species extends beyond the classical core of Amazonian areas of endemism, representing the easternmost lineage in the group. In terms of biogeographic structure, M.pernigra is associated with multiple adjacent areas of endemism, including Inambari, Rondônia, Tapajós, and Xingú. This trans-interfluvial distribution suggests a distinct historical trajectory, potentially involving either a more recent range expansion or greater dispersal ability relative to other species in the complex, rather than strict isolation by major river barriers.
Meliponapicea sp. nov. is primarily distributed in western Amazonia, with most records concentrated in the Tefé region. Its range extends eastwards to the Purus and Jacaré rivers, where it comes into contact with M.abunensis, forming a narrow transition zone characterized by intermediate phenotypes. Westwards, the species reaches the Juruá-Jutaí interfluve, while to the north it occurs in the Maraã-Japurá region. The southern limits of its distribution remain poorly documented. From a biogeographic standpoint, M.piceasp. nov. is mainly associated with the Napo area of endemism, with additional marginal occurrences in the Inambari region. This pattern is consistent with a western Amazonian lineage whose present distribution has been shaped by interfluvial boundaries, with limited secondary contact occurring along the Purus basin.
Meliponaatrofulva sp. nov. exhibits a geographically restricted distribution, being confined to the Negro-Branco interfluve in northwestern Amazonia. Its range extends westwards to the Santa Isabel do Rio Negro-Rio Daraã region and eastwards to the Curicuriari (Camanaú) rivers, while southwards it reaches Maraã and the lower Japurá basin. The northern limits of its distribution remain unknown. Notably, the known distribution of M.atrofulvasp. nov. corresponds closely to the Jaú area of endemism, one of the most clearly delimited interfluvial regions in the Amazon. This strong geographic coherence supports the interpretation of M.atrofulvasp. nov. as a lineage shaped primarily by long-term isolation within a single interfluvial unit.
The biogeographic patterns discussed here do not result from a formal biogeographic analysis, but rather from a careful interpretation of empirically documented species distributions within the Meliponaseminigra complex. Our discussion is grounded on verified occurrence records explicitly associated with recognized Amazonian areas of endemism, avoiding ad hoc assumptions or vague historical narratives. Even under this conservative framework, clear spatial structure emerges, with most species showing non-random associations with specific interfluvial regions as already demonstrated for other groups (e.g., Silva et al. 2005; Naka 2011; Borges et al. 2012; Braga et al. 2022). From a taxonomic perspective, these patterns provide independent, geography-based support for species limits inferred from morphology. Several lineages exhibit distributions largely restricted to single areas of endemism (e.g., Guiana, Jaú, Napo, or Rondônia), whereas others display broader or marginal ranges shaped by secondary contact, recent dispersal, or localized introgression. Notably, the Inambari region repeatedly appears as a biogeographic “hub”, hosting multiple species and several contact zones, a pattern widely observed in other Amazonian taxa and consistent with its role as a zone of historical connectivity (Brasil et al. 2017; Silva et al. 2022; Rego et al. 2026).
Exceptions to strict interfluvial confinement are also informative. Meliponapernigra remains the least geographically structured lineage in the complex, spanning multiple areas of endemism and suggesting a distinct evolutionary history that may involve recent range expansion or enhanced dispersal capacity. In contrast, marginal records observed for other species are more parsimoniously interpreted as the result of secondary dispersal, fine-scale imprecision in area delimitation, or anthropogenic nest translocation driven by intensive meliponiculture. It is also important to note that such patterns may be further influenced by human-mediated movement of colonies, which can artificially expand or blur natural distributional limits. Rather than constituting evidence against interfluvial structure, these occurrences likely reflect a combination of natural and anthropogenic processes. Taken together, these distributional patterns highlight the relevance of Amazonian interfluves as a meaningful framework for interpreting diversification within the M.seminigra complex, while also emphasizing the need for integrative approaches combining morphology, population-level genetic data, and explicit biogeographic modeling to formally test the historical processes underlying these patterns.
3.6. Conservation of genetic diversity
The consistently low (pairwise K80 distances below 0.01) levels of intraspecific genetic diversity observed across all groups, combined with pronounced interspecific divergence, underscore the importance of conservation strategies that treat each specific unit as an independent evolutionary lineage. These findings carry far-reaching implications for the long-term preservation of the genetic integrity and phylogenetic diversity of this group, particularly in light of the rapid expansion of meliponiculture across the Amazon and adjacent areas and the increasing transportation and commercialization of stingless-bee colonies beyond their native ranges (Jaffé et al. 2015; Quezada-Euán et al. 2022).
From a conservation genetics perspective, the patterns documented here suggest that each taxonomic unit likely represents a distinct evolutionary trajectory shaped by its own demographic history, ecological conditions, and biogeographical constraints. The extremely low genetic variability detected within several species heightens concern, as it may reflect historical bottlenecks, restricted gene flow, or even sampling biases associated with geographically limited datasets and managed colonies. Nevertheless, because the present results are based on a single mitochondrial marker, these alternative explanations should be evaluated using broader geographical sampling and nuclear or genome-wide data. Regardless of origin, reduced genetic variation can diminish adaptive potential, increase susceptibility to stochastic events, and ultimately compromise the evolutionary resilience of populations (Liu 2022; Dussex et al. 2025).
In this context, conservation planning should prioritize the maintenance of both taxonomic and genetic boundaries, ensuring that management interventions, whether through meliponiculture, translocation, or conservation breeding, avoid unintentional admixture among divergent lineages. The movement of managed colonies may weaken natural geographical genetic structure, bring previously allopatric lineages into secondary contact, and promote reproductive interference or hybridization (Nascimento et al. 2000; Paul et al. 2023; Wongsa et al. 2024). The recognition of these units as distinct evolutionary lineages becomes especially critical to guide policy decisions and technical recommendations in meliponiculture, prevent homogenization of locally adapted populations, and safeguard the evolutionary processes that generate and maintain biodiversity.
Furthermore, the pronounced interspecific divergence recovered here reinforces the necessity of adopting a lineage-centered approach to conservation. Rather than viewing these taxa as interchangeable components of a single species complex, their deep genetic separation calls for tailored management strategies that reflect their independent evolutionary histories. Complementary efforts should focus on expanding sampling to include wild populations across their full geographical ranges, an essential step for accurately assessing genetic health, detecting cryptic diversity, and refining demographic and biogeographical models.
The results of the present study provide a solid foundation for the development and refinement of conservation actions that target not only the taxa addressed here, but also their respective areas of distribution. This is particularly relevant given the endemic nature of several species and the potential consequences of anthropogenic activities on both natural and managed populations. Habitat loss and fragmentation, pesticide exposure, climate change, competition with managed bees, and the spread of pathogens and introduced organisms are among the principal threats documented for stingless bees (Freitas et al. 2009; Toledo-Hernández et al. 2022). Effective conservation strategies should therefore aim to preserve not only genetic and population integrity, but also the specific habitats that likely acted in concert to drive the speciation of these unique evolutionary lineages. Moreover, further studies are required to better understand patterns of gene flow both among species and within populations. Such efforts are essential to determine whether sufficient levels of genetic variability and diversity persist to maintain long-term population viability. Improved knowledge of these processes will allow conservation actions to be more accurately targeted, thereby increasing their effectiveness and reducing unintended impacts on locally adapted lineages.
4. Declarations
Ethical statement. Not applicable.
Competing interests. The authors declare no conflicts of interest.
Data accessibility. All DNA sequences used in this study are publicly available in GenBank, and their accession numbers are provided in Table SS1. The dataset analysed here was entirely compiled from previously published sources, primarily Francini et al. (2022), and no new sequences were generated as part of this study. The sequence alignment, phylogenetic trees, and R scripts used for species delimitation analyses are openly available in the Zenodo repository at: https://doi.org/10.5281/zenodo.20366366. These materials ensure full reproducibility of the analytical workflow presented in this study. All data used in this study are publicly accessible, and no restrictions apply to their reuse.
Funding Statement. We thank the Instituto Nacional de Pesquisas da Amazônia (INPA) for laboratory and financial support (internal project PRJ 12.313). Financial support was also provided by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) through the Edital Universal (process 407241/2025-6), the INCT BioDossel: diversidade de insetos na copa das árvores (process 406833/2022-2), and the CNPq/CONFAP-FAPEAM PROTAX 24/2024. Additional support was granted by the Fundação de Amparo à Pesquisa do Estado do Amazonas (FAPEAM) (POSGRAD program) and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) (PROAP program, Finance Code 001). MLO is supported by a CNPq Research Productivity Fellowship (proc. 311016/2023-5). JASS and JCCO are supported by CAPES Doctoral Scholarships (Finance Code 001).
Authors' Contributions. JASS: Conceptualization, Formal analysis, Investigation, Methodology, Project administration, Writing – Original Draft, Writing – Review and Editing. DSN: Methodology, Validation, Writing – Review and Editing. IBF: Data Curation, Investigation, Writing – Review and Editing. JSCO: Writing – Review and Editing. RMOA: Writing – Review and Editing. GACZ: Funding Acquisition, Supervision, Writing – Review and Editing. MLO: Funding Acquisition, Supervision, Writing – Review and Editing. All authors approved the final version of the manuscript and agreed to be accountable for all aspects of the work.
5. Acknowledgments
We thank Eduardo Andrade Botelho de Almeida for the loan of the specimens for this study from Coleção Prof. J.M.F. Camargo (RPSP). We also thank Victoria Tura for kindly providing the shapefile of the Amazonian areas of endemism. We extend our sincere gratitude to the anonymous reviewers for their thorough evaluations and constructive suggestions, which greatly improved the clarity, rigor, and overall quality of this manuscript. Their expertise and careful consideration significantly contributed to strengthening the final version of this work. Furthermore, to the meliponiculturists who provided samples.
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File S1
: .cocx
: Full transcription of labels of all examined specimens, including collection data, geographic coordinates, and institutional catalog numbers.
https://binary.pensoft.net/file/1793015This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited. Santos-Silva JA, Nogueira DS, Francini IB, Oliveira JCC, Alves RMO, Carvalho-Zilse GA, Oliveira ML (2026)10.3897/asp.84.e201039.suppl2228A008D-C3C9-55F0-85A3-136980BA2667
Table SS1
: .cocx
: List of all genetic sequences used in this study, including species name, GenBank accession number, gene/marker, voucher/specimen code, and geographic origin.
https://binary.pensoft.net/file/1793016This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited. Santos-Silva JA, Nogueira DS, Francini IB, Oliveira JCC, Alves RMO, Carvalho-Zilse GA, Oliveira ML (2026)