DOI: 10.3897/asp.82.e116205

Authors: Valentine Mewis, Peter Neu, Thomas Schmitt

Abstract: The understanding of cryptic species complexes with their often highly interesting biogeographical patterns is still a crucial aspect in evolutionary biology and related disciplines. Trichoptera are a group of insects particularly rich in unresolved groups. One example is the Wormaldia occipitalis species complex in which morphological studies suggest remarkable patterns of differentiation. In order to determine genetic differentiation and phylogenetic structure, one mitochondrial (COI) and two nuclear markers (CAD, wingless) were analysed for the W. occipitalis species complex around the Alps and northwards to Germany. The morphology-defined differentiation pattern was also observed at the genetic level. The morphologically well distinguishable groups W. occipitalis and W. subterranea were identified as two genetically distant monophyletic groups with about 10 % genetic divergence of the mitochondrial marker. These two taxa likely split during the Mio-Pliocene transition. Genetic analyses revealed four subgroups within W. occipitalis and three within W. subterranea. Several possible postglacial dispersal and differentiation processes are proposed. Thereby, W. occipitalis from the western Alps and individuals of W. subterranea from the eastern Alps spread towards Central Europe after the Last Glacial Maximum. Today, both species groups are sympatric and partly syntopic in the recolonised area in western Germany but apparently allopatric in their centres of origin around the Alps. The high genetic differentiation, lack of detectable genetic evidence for hybridisation, their syntopic distribution and the morphological distinctness indicate that W. occipitalis and W. subterranea are two distinct species. The genetically determined subgroups might represent subspecies.

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DOI: 10.3897/asp.82.e114286

Authors: Pedro Bonfá-Neto, Frederico Falcão Salles, Albane Vilarino

Abstract: Asymmetrical genitalia are reported from major Trichoptera subgroups and evolved multiple times independently. In Oecetis, it is a characteristic of the insconpicua group. However, certain species in other species groups also evolved an asymmetrical spiny projection on the phallotheca. Here, two new species with an asymmetric projection are described in the falicia group from the Brazilian Atlantic Forest, Espírito Santo state. Their phylogenetic relationships were investigated through a Bayesian analysis combining COI and morphological data. Additionally, we provide new records of Oecetis connata, O. inconspicua and O. paranensis from the Espírito Santo state, and O. connata and O. flinti from Minas Gerais state. Oecetis capixaba sp. nov. is placed with low support as the sister species of O. acanthostema, both presenting stout spine-like setae on the inner surface of the inferior appendage; the new species is diagnosed by the long spine-like setae on the inferior appendage, the narrow dorsolateral process of segment IX, and the phallic apparatus without apical projections. Oecetis ruschii sp. nov. is placed as a sister group of the clade including O. facilia and O. furcata, both presenting forked dorsolateral processes of segment IX; the new species is diagnosed by the dorsolateral process of segment IX with a lateral branching and the apex of inferior appendage wide and triangular. While the phylogenetic results should be considered preliminary and interpreted with caution, they indicate that the asymmetric projection evolved multiple times convergently in the avara, punctata, and falicia groups. The asymmetric genitalia in the falicia group seems to have evolved only in males since no correspondent asymmetry is described for females. The function of the asymmetrical projection remains unknown.

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DOI: 10.3897/asp.82.e112587

Authors: Albane Vilarino, Adolfo R. Calor

Abstract: Geometric morphometric statistics have been employed to reduce the subjectivity of visual evaluations in taxonomy. Taxonomy in most insect groups relies strongly on male genitalia morphology which is often the structure with most data available, which is also true to caddisfly taxonomy. Here we revise the caddisfly subgenus Xiphocentron (Sphagocentron) adding five new species after 40 years: X. dactylum sp. nov., X. eurybrachium sp. nov., X. tapanti sp. nov., and X. tuxtla sp. nov. Additionally, we describe a new X. (Antillotrichia): X. drepanum sp. nov. from French Guiana and provide new species records of Xiphocentronidae from Bolivia, Costa Rica and Ecuador. We performed exploratory geometric morphometric analysis on the male genitalia’s preanal appendage to characterize the shape differences among the species, and to investigate its utility to classify species to subgenera. In order to infer species relationship and assess if shape congruences are due to phylogenetic signal or convergence data from 100 landmarks and semilandmarks, and 30 discrete characters were used to generate a phylogenetic hypothesis. The morphometry partially supports the subgenera delimitations, but the Antillotrichia subgenus greatly overlapped with other subgenera. The discriminant analysis overall classification correctness was 64%. Some suggested phenotypic groups were due to convergence. According to the preanal appendage morphometry, X. (Antillotrichia) fuscum is a Sphagocentron species. The phylogenetic analysis recovered Sphagocentron as monophyletic, but not Antillotrichia. Sphagocentron subgenus was placed within a clade of several Antillotrichia species, with X. (A.) fuscum as the sister of the other Sphagocentron species, although support values were low.

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DOI: 10.3897/asp.81.e110014

Authors: Steffen U. Pauls, Wolfram Graf, Anna E. Hjalmarsson, Alan Lemmon, Emily Moriarty Lemmon, Malte Petersen, Simon Vitecek, Paul B. Frandsen

Abstract: Streams represent a special case of directional environmental gradients where ecological opportunity for diversification may be associated with upstream and downstream dispersal into habitats that differ in selective pressures. Temperature, current velocity and variability, sediment erosion dynamics and oxygen saturation are key environmental parameters that change in predictable ways from springs to river mouth. Many aquatic insects occupy specific longitudinal regions along these gradients, indicating a high degree of adaptation to these specific environmental conditions. In caddisflies, the evolution of tracheal gills in larval and pupal stages may be a major driver in oxygen uptake efficiency and ecological diversification. Here we study the evolution of larval gill structure in the Rhyacophila vulgaris species group using phylogenomic methods. Based on anchored hybrid enrichment, we sequenced 97 kbp of data representing 159 independent nuclear protein coding gene regions to infer the phylogeny of the R. vulgaris species group, whose species exhibit both high diversity of gill types and varied longitudinal preferences. We find that the different gill types evolved independently as derived characters in the genus and that gill structure is linked to the longitudinal habitat preference, thereby serving as a possible ecological key innovation in the R. vulgaris group.

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DOI: 10.3897/asp.80.e76559

Authors: Paula Dias Moreira, Leandro Lourenço Dumas, María Paula Rozo, Gleison Robson Desidério, Daniela Maeda Takiya

Abstract: Chimarra Stephens, 1829 is the largest genus of the Philopotamidae with about 930 species and cosmopolitan distribution. Recent taxonomic revisions have subdivided the genus into four subgenera: Chimarra, Curgia Walker, 1860, Chimarrita Blahnik, 1997, and Otarrha Blahnik, 2002, the last three restricted to the New World. In this paper, we describe and illustrate two new species of Chimarra from Brazil, C. (Otarrha) paraodonta sp. nov. from Rio de Janeiro State and C. (Chimarrita) truncata sp. nov. from Amazonas and Pará states. Partial sequences of cytochrome oxidase subunit I (COI, DNA barcodes) were generated and integrated with morphological evidence to delimit the new species and evaluate their phylogenetic relationships within the genus. A maximum likelihood analysis of 48 COI sequences representing 19 species of Chimarra corroborated their subgeneric assignment based on morphology and highlighted their putative sister species. Both new species showed high K2P divergences when compared to their sister species: Chimarra (O.) paraodonta sp. nov. and C. (O.) odonta (17.4–21.3%) and Chimarra (C.) truncata sp. nov. and C. (C.) simpliciforma (20.0–21.3%). These distances are comparable to the range of interspecific distances calculated for the whole genus (13.6–22.7%), adding support to their description as new species. This analysis was especially important because of the high morphological similarity of C. paraodonta sp. nov. and C. odonta. Finally, analysis of the sequences of Chimarra odonta suggests that the nominal species may represent a complex of cryptic species with high intraspecific divergences (up to 18.1%), with at least two of those lineages co-occurring with C. paraodonta sp. nov. at Parque Nacional do Itatiaia.

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