Corresponding author: Atilano Contreras-Ramos ( acontreras@ib.unam.mx ) Academic editor: Ricardo Pérez-de la Fuente
© 2022 Caleb Califre Martins, Horst Aspöck, Ulrike Aspöck, Atilano Contreras-Ramos.
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The genus Alena Navás, 1916, is considered the most distinct genus of Raphidiidae, because of the uncommon shape of its male genital sclerites and its geographic distribution restricted to the southwestern U.S.A. and western Mexico. Herein, we present a new species of the subgenus Aztekoraphidia U. Aspöck and H. Aspöck, 1970, – Alena (Aztekoraphidia) alanae sp. nov. Based on this discovery we present a detailed morphological study and the first morphological phylogeny of Alena. Our results recover this genus as monophyletic, including the subgenus Aztekoraphidia as sister to a clade composed by the other two monotypic subgenera, Alena s.s. Navás, 1916, and Mexicoraphidia U. Aspöck and H. Aspöck, 1970. We also provide a hypothesis about the biogeographic history of the group, which advocates that species of Alena are strongly associated with central Mexico and their ancestors were probably widely distributed through western North America in the past, of which only a few small groups survived in glacial refuges.
Biodiversity, central Mexico, glacial refuges, morphology, western North America, Neuropterida
Alena Navás, 1916, is a small snakefly genus of the family Raphidiidae, which is restricted to southernmost North America, especially western Mexico (U. Aspöck and H. Aspöck 2013). Despite the molecular phylogeny of Raphidiidae by
The genus Alena was described by Navás in 1916, and originally included the type species, Alena distincta (Banks, 1911), and Al. minuta (Banks, 1903), both previously included in Raphidia Linnaeus, 1758. However, its oldest known species is actually Alena (Az.) australis (Banks, 1895), which implies more than 120 years of history of a group with only ten described species up to now. When compared with other genera of Raphidiidae, Alena is still poorly known, although its latest study was published only a few years ago by U. Aspöck and H. Aspöck (2013), who stated: “snakeflies are among the rarest insects in Mexico, and, in particular, every record of a specimen of Alena merits attention … the finding of any new species of Alena was and will always remain an exciting event”. In response to the paucity of studies on this genus, aiming to contribute to the general phylogenetic understanding of Raphidiidae, herein we describe Alena (Az.) alanae sp. nov., increasing the number of species of this genus to 11. We also present the first morphological phylogenetic analysis of Alena, with a hypothesis about its biogeographic history. A review of the Mexican snakeflies is nearly concluded and will be published elsewhere.
Adult specimens of Alena, Agulla Navás, 1914, and Indianoinocellia U. Aspöck and H. Aspöck, 1970, species had their external morphology and its genital structures compared in detail. For the morphological study of genitalia, the last five abdominal segments were dissected in a Petri dish with glycerin under a Leica M16 stereomicroscope, then they were cleared with a 10% potassium hydroxide (KOH) solution, washed in sequence with distilled water, 10% acetic acid, and 70% ethyl alcohol. Posteriorly, the genital structures were observed and stored in micro-vials with glycerin, and pinned below the respective specimen. High-resolution images from the new species of Alena were produced with a Leica DC500 digital camera attached to a Leica M16 stereomicroscope; the photographs were stacked and processed with the software Auto-Montage Pro v5.02 (Leica Microsystems, Wetzlar, Germany), and the final image was edited in the software Photoshop CS. Drawings were made using a Zeiss Stemi SV11 stereomicroscope, and then scanned and vectored in the software Adobe Illustrator CS. The studied specimens are deposited in the Colección Nacional de Insectos of Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City (CNIN-UNAM).
Wing venation terminology follows H.
For the phylogenetic analysis of Alena Navás, 1916, all 11 species were included as the ingroup, with Indianoinocellia mayana U. Aspöck et al., 1992 (Inocelliidae) and Agulla (Ag.) bicolor (Albarda, 1891) as outgroups, while the Inocelliidae species was used to root the tree under rooting procedures of
The characters used for the phylogenetic analysis were determined through a detailed comparative study of the morphology of Indianoinocellia, Agulla, and Alena species. A matrix (Table
Data matrix of adult morphological characters for the genus Alena Navás, 1916 (Raphidioptera: Raphidiidae) phylogenetic analysis (?, missing data; –, inapplicable character).
Species | Characters and states | |||||||||||||||||||||||||||||||||||
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 34 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | |
Indianoinocellia mayana | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | – | 0 | 0 | 0 | 0 | 0 | 0 | - | - | - | - | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Agulla (Ag.) bicolor | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | – | 0 | 0 | 0 | 0 | 0 | – | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 |
Al. (Al.) distincta | 0 | 1 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | – | 1 | 1 | 2 | 1 | 0 | 0 | 1 | 2 | 2 |
Al. (Mx.) americana | 0 | 1 | 2 | 2 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | – | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 0 |
Al. (Az.) alanae sp.nov. | 0 | 1 | 2 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 2 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 1 | 1 | – | 1 | 1 | 1 | 1 | 0 | 0 | 2 | 1 | 1 |
Al. (Az.) michoacana | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 2 | 0 | 0 | 2 | 2 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 2 | 1 | 1 | 1 | 1 | 1 | ? | ? | ? | ? | ? |
Al. (Az.) horstaspoecki | 0 | 1 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 2 | 0 | 0 | 2 | 2 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 2 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 2 | 1 | 1 |
Al. (Az.) schremmeri | 0 | 1 | 2 | 2 | 1 | 1 | 1 | 0 | 1 | 2 | 1 | 0 | 0 | 2 | 1 | 1 | 1 | 2 | 1 | 0 | 1 | 0 | 0 | 0 | 1 | 1 | – | 1 | 1 | 1 | 0 | 0 | 0 | 2 | 1 | 1 |
Al. (Az.) caudata | 0 | 1 | 2 | 2 | 1 | 1 | 0 | 1 | 1 | 2 | 1 | 0 | 0 | 2 | 1 | 1 | 1 | 2 | 1 | 0 | 1 | 0 | 1 | 1 | 1 | 1 | – | 1 | 1 | 1 | 1 | 0 | 0 | 2 | 1 | 1 |
Al. (Az.) infundibulata | 0 | 1 | 2 | 2 | 1 | 1 | 0 | 0 | 1 | 2 | 1 | 0 | 0 | 2 | 1 | 2 | 1 | 2 | 1 | 0 | 1 | 0 | 1 | 1 | 1 | ? | – | 1 | 1 | 1 | 1 | 0 | 1 | 2 | 1 | 1 |
Al. (Az.) minuta | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 2 | 2 | 1 | 0 | 2 | 1 | ? | 1 | 2 | 1 | 0 | 1 | 0 | 1 | 1 | 1 | 1 | – | 2 | 2 | 3 | 1 | 0 | 0 | 2 | 1 | 1 |
Al. (Az.) australis | 1 | 0 | 1 | 1 | 2 | 1 | 1 | 1 | 1 | 2 | 2 | 1 | 1 | 2 | 0 | 0 | 1 | 2 | 1 | 0 | 1 | 0 | 1 | 1 | 1 | 1 | – | 2 | 2 | 3 | 1 | 2 | 1 | 2 | 1 | 1 |
Al. (Az.) tenochtitlana | 1 | 0 | 1 | 1 | 2 | 1 | 1 | 1 | 1 | 2 | 2 | 1 | 1 | 2 | 0 | 0 | 1 | 2 | 1 | 0 | 1 | 0 | 1 | 1 | 1 | 2 | 0 | 2 | 2 | 3 | 1 | 2 | 1 | 2 | 1 | 1 |
Analyses were first performed with characters treated with equal weight; subsequent analyses were performed using implied weighting with different values of constant k (3–10), prioritizing character sets with a greater congruence reflecting in the reduction of information loss on phylogenetic relationships in the consensus (
Bremer support or BS (
To generate a hypothesis for the biogeographical history of Alena we used the most parsimonious tree topology recovered in the phylogenetic analysis to perform a statistical dispersal–vicariance analysis (S-DIVA) in RASP software (
Alena Navás, 1916.
Raphidia distincta Banks, 1911 (by original designation). — Subgenera included: Alena s.s. Navás, 1916; Aztekoraphidia U. Aspöck and H. Aspöck, 1970; Mexicoraphidia U. Aspöck and H. Aspöck, 1970. — Species included: Alena (Alena) distincta (Banks, 1911), Alena (Mexicoraphidia) americana Carpenter, 1958, Alena (Aztekoraphidia) alanae sp. nov., Al. (Az.) australis (Banks, 1895), Al. (Az.) caudata (Navás, 1914), Al. (Az.) horstaspoecki U. Aspöck and Contreras-Ramos, 2014; Al. (Az.) infundibulata U. Aspöck et al., 1994; Al. (Az.) michoacana U. Aspöck and H. Aspöck, 2013; Al. (Az.) minuta (Banks, 1903); Al. (Az.) schremmeri U. Aspöck et al., 1994; Al. (Az.) tenochtitlana (U. Aspöck and H. Aspöck, 1978).
Holotype. ♂ (pinned), “México: Estado de México: Nanchititla, Parque Sierra de Nanchititla, 18°51’42.5”N, 100°25’38.1”W, 1758 m, 14.VIII.2018, trampa de Luz, F. Villagomez” (CNIN). Allotype. ♀ (pinned), same data as holotype. Paratypes. 3♂♂ (1 pinned and 2 in alcohol), same data as holotype.
Habitus mostly blackish-brown, with some pale yellow elements (pedicel, scape, clypeus, pterostigma) and abdominal apex amber (Fig.
Alena (Aztekoraphidia) alanae sp. nov., holotype male. A: habitus, lateral view; B: wings; C: head, dorsal view. A1–A2, anal veins; av, apical vein; CuA, cubitus anterior; CuP, cubitus posterior; MA, media anterior; MP, media posterior; pt, pterostigma; RA, radius anterior; RP, radius posterior; Sc, subcosta.
Male measurements (n=4). Body length: 8.6–8.9 mm; forewing length: 7.4–7.7 mm; hind wing length: 6.3–6.7 mm. Female measurements (n=1): Body length: 10.3 mm; forewing length: 9.1 mm; hind wing length: 7.3 mm. — Head (Fig.
Alena (Aztekoraphidia) alanae sp. nov. Male genitalia, A: dorsal view; B: ventral view; C: lateral view. Female genitalia, D: lateral view; E: ventral view; F: complex of bursa copulatrix, lateral view. ab, atrium bursae; bs, basal sclerite of gonocoxite 9; ect, ectoproct; gr, glandulae receptaculi; rs, receptaculum seminis; S7–S9, seventh-ninth sternites; sb, sacculus bursae; T7–T9, seventh-ninth tergites.
Unknown.
This new species is dedicated to the first author’s wife, Alana C. D. Brunini, who has been an unconditional source of support in all his academic and non-academic ventures during these 16 years together.
Mexico (Estado de México) (Fig.
The new species was collected at an altitude of 1758 m at light trap. The region where Alena (Az.) alanae sp. nov. was encountered is a large mountainous area, with pine-oak vegetation within an extensive part of low deciduous forest, especially Pinus and Quercus. This region is considered temperate subhumid, with average annual temperature greater than 18 °C – coldest month temperature less than 18 °C, hottest month temperature greater than 22 °C –, and annual precipitation between 500 and 2,500 mm (CONABIO 2021).
Because of the displacement of the gx IX apex above the origin of the gst IX in males, plus females with atrium-bursae tube-like, receptaculum seminis adhered to atrium bursae, and glandulae receptaculi elongated, Alena alanae sp. nov. clearly belongs to the subgenus Aztekoraphidia. This new species has the base of MA on the hind wing as a crossvein, which differentiates it from other Alena species with base of MA as a longitudinal vein, i.e., Al. (Mx.) americana, Al. (Az.) infundibulata, Al. (Az.) caudata, Al. (Az.) horstaspoecki, and Al. (Az.) schremmeri. Alena (Az.) alanae sp. nov. possesses an apical vein on pterostigma, separating it from Al. (Az.) australis, Al. (Az.) michoacana, Al. (Az.) minuta (Banks, 1903), and Al. (Az.) tenochtitlana, species without such vein.
Alena (Az.) alanae sp. nov. has no evident relationship to any of the other Aztekoraphidia species, and may be separated from all other Alena species by the shape of the distinctly male large gst IX, which is subquadrangular in lateral view, especially in its broad base, and curved dorsad and inward. All other species of Aztekoraphidia have gst IX subcylindrically, arm-like, and only in Al. tenochtitlana these structures are weakly curved inward. Alena (Al.) distincta and Al. (Mx.) americana have male gst IX bifurcated apically which clearly separates these species from Al. (Az.) alanae. Females of the new species have the glandulae receptaculi apically club-like, which is not observable in other Aztekoraphidia species; only Al. (Az.) horstaspoecki has the apex of glandulae receptaculi enlarged, but it is smaller when compared with that from the new species.
Fig.
Mexico (Michoacán; Jalisco (new record))
“México: Jalisco: Venustiano Carranza, 20 KM W(est) Cd. Guzmán, 19°38.6’N, 103°40.1”W, 1955 m, 14.VI.2013, Bosque pino, L. Cervantes and D. Brzoska”, 1♂ (alcohol) (CNIN).
U.S.A. (Arizona; Colorado; New Mexico; Utah); Mexico (Chihuahua; Durango; Estado de México (new record); Jalisco (new record)).
“México: Jalisco: San Sebastián del Oeste, Camino a Santiago de Pinos, BP, 1500 m, 9.VII.1997, ex. Luz, J. L. Navarrete”, 1♀ (pinned) (CNIN); “26 Km E(ast) Talpa, 1580 m, 16.VII.1993, A. Rodriguez and F. A. Noguera”, 1♀ (pinned) (CNIN). “Distrito Federal: Del(egación) Cuajimalpa, Parque Nacional Desierto de los Leones, Río San Borja, 19°18’27”N, 99°18’45”W, 2971 m, 16.VI.2007, R. Juaréz and M. Razo”, 1♀ (pinned) (CNIN).
Mexico (Morelos; Puebla (new record)).
“México: Puebla: 3 Km al N(orth)W(est) de Tecalzingo, 18°43’91.3”N, 97°41”02.1”W, 3-4.VI.1995, E. Barrera”, 1♀ (pinned) (CNIN).
All the cladistic analyses performed, either using equal weighting or using implicit weighting with different constant k values (3–10), recovered the same most parsimonious tree (77 steps in length (L), consistence index (CI) of 70, and retention index (RI) of 73) (Fig.
Phylogenetic relationship of Alena Navás, 1916 (Raphidioptera: Raphidiidae) and its genitalic evolution. Most parsimonious and unique tree (number of steps = 77, consistency index (CI) = 70, retention index (RI) = 73) of equal and implied weight analyses using constant k = 3-10. Character changes are marked on branches, red above = character numbers, and black below = character state. Forward unequivocal changes (black circles) and reversed or multiple changes (white circles) are shown. Bremer values of branch support are presented below nodes in green. Male figures from top to bottom, Al. (Al.) distincta, Al. (Mx.) americana, Al. (Az.) alanae sp. nov., Al. (Az.) michoacana, Al. (Az.) tenochtitlana, and Al. (Az.) caudata. Female figures from top to bottom Al. (Al.) distincta, Al. (Mx.) americana, Al. (Az.) alanae sp. nov., Al. (Az.) horstaspoecki, Al. (Az.) minuta, and Al. (Az.) caudata (Figures modified from H.
The monophyly of Alena is well-supported (BS = 9) by the following 16 autapomorphies: wings with apical vein on pterostigma (char. 2:1), forewing with second ra-rp crossvein in the level of the median region of pterostigma (char. 3:2); males with the length of sternite VIII corresponding to 3/4–1/2 of the tergite VIII length (char. 5:1), tergite and sternite of abdominal segment IX separated (char. 6:1), tergite IX with median suture on dorsal region (char. 7:1); gx IX 1.2–1.5× longer than wide (char. 10:1), with distinct basal sclerites (char. 9:1), and basal third approximately 2/3 as wide as its median area (char. 11:1); gst IX subquadrangular (char. 18:1); gph IX (when composing the “hypovalva”) with tapered apex (char. 24:1), and broadly inserted on the basal sclerites of gx IX (char. 25:1); complex of gx X completely amalgamated with gph IX (char. 26:1); ectoproct rectangular in dorsal view (char. 28:1), and subtriangular in lateral view (char. 30:1), with median V-shaped incision on posterior margin (char. 29:1), and trichobothria reduced or absent (char. 31:1).
Mexicoraphidia and Alena s.s., both monotypic subgenera of Alena, were recovered in a clade (BS = 1) sister to the species belonging to the third subgenus, Aztekoraphidia. The clade composed of Mexicoraphidia and Alena s.s. is supported by males with apex of gx IX located below or before the gst IX base (char. 14:1), gst IX with bifurcated apex (char. 20:1), and females with receptaculum seminis absent or strongly reduced (char. 35:2), all of them synapomorphies. Aztekoraphidia (BS = 2) has its monophyly supported by males with apex of gx IX located above or in front of gst IX (char. 14:2), and females with tube-like atrium bursae (char. 34:2), receptaculum seminis adhered or fused with the atrium bursae (char. 35:1), and glandulae receptaculi elongated (char. 36:1).
Among the species belonging to Aztekoraphidia, Al. (Az.) alanae sp. nov. is considered sister to the remaining eight species, which share males with arm-like gst IX (char. 18:2), that have its base approximately as large as its apex (char. 19:1), as well as gph IX with divergent apex (char. 23:1). Alena (Az.) michoacana was recovered as sister to Al. (Az.) horstaspoecki in a clade supported by three synapomorphies, males with ridge of gst IX poorly developed (char. 17:2), apex of gph IX located before the tergite IX apex (char. 22:1), and complex of gx X (when not amalgamated with gph IX) bearing projections (char. 27:1). This last clade is also supported by males with sternite IX indistinct (char. 8:1), apex of gph IX rhomboid (char. 24:0), and complex of gx X located apically to gph IX (char. 26:2), which are independently present in other species.
The remaining six species of Aztekoraphidia share males with gx IX at least 1.7× longer than wide (char. 10:2), and are divided in two clades with three species each. The first clade is composed of Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana). These three species have as main characteristics, both wings with two-colored pterostigma (char. 1:1), and lacking apical vein (char. 2:1), forewing with second ra-rp crossvein located apically to pterostigma (char. 3:1); males with gx IX presenting the basal third elongated (char. 12:1), and about 1/2 as wide as its median region (char. 11:2), as well as the ectoproct trapezoidal in dorsal view (char. 28:2), with median region of posterior margin convex, in this same view (char. 29:2), and arm-like in lateral view (char. 30:3). Alena (Az.) australis and Al. (Az.) tenochtitlana share three synapomorphies – males with sternite VIII with 1/3 of the tergite VIII length (char. 5:2), gx IX with ventral margin concave on median region (char. 13:1), and female with tergite VIII fused ventrally, forming a ring (char. 32:2) –, and two homoplastic characters also present in other Alena species, males with sternite IX indistinct (char. 8:1), and females with base of tergite VIII clearly larger than its median region, in lateral view (char. 33:1). The second clade has Al. (Az.) caudata sister to Al. (Az.) infundibulata – sharing a reversion, male tergite IX without median suture (char. 7:0) –, and both species sister to Al. (Az.) schremmeri, making a group supported by base of MA on hind wing present as longitudinal vein (char. 4:2), and males with gx IX with dorsoposterior tapered process (char. 16:1), and with elongated apex (char. 15:1).
The S-DIVA analysis for the biogeographical history of Alena (Fig.
Historical biogeography of Alena Navás, 1916 (Neuroptera: Raphidiidae). A: chronogram showing intergeneric relationships within Alena Navás, 1916 (based on the topology results recovered in the equal and implied weight analysis using constant k values of 3–10), reconstructed ancestral areas mapped for each node. B: biogeographic provinces of Mexico and southwestern U.S.A., after
Concerning the vicariance events, they occurred once in the nodes of Al. (Al.) distincta + Al. (Mx.) americana; Aztekoraphidia; Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana); and Al. (Az.) caudata + Al. (Az.) infundibulata. The extinction events occurred once in the nodes of Alena, and Al. (Az.) schremmeri + (Al. (Az.) caudata + Al. (Az.) infundibulata).
The ancestral area of Alena is composed of the Californian (southwest U.S.A) and Transmexican Volcanic Belt, Balsas Basin, and Sierra Madre del Sur provinces from central Mexico.
Alena (Al.) distincta, the only species of the subgenus Alena s.s., occurs in the California province, extreme north region of the genus distribution; while its sister species and only representative of Mexicoraphidia – Al. (Mx.) americana –, occurs in the Transmexican Volcanic Belt and Balsas Basin provinces, in central Mexico. The disjunctive distribution between these species recovered an ancestral area composed of northern and southern provinces.
The biogeographic history of the subgenus Aztekoraphidia is strongly associated with central Mexico, involving the Transmexican Volcanic Belt, Balsas Basin, and the Sierra Madre del Sur provinces. The species of Aztekoraphidia except Al. (Az.) alanae sp. nov. are also associated with this general region, however, their biogeographic ancestral area does not include the Balsas Basin province.
Alena (Az.) horstaspoecki and Al. (Az.) michoacana occur in the same biogeographic province, the Transmexican Volcanic Belt, hypothesized as the area of occurrence of their stem species. The other clade of Aztekoraphidia, composed of six species, presented a doubtful ancestral area. Alena (Az.) schremmeri, Al. (Az.) caudata, and Al. (Az.) infundibulata compose a clade strongly associated with the Transmexican Volcanic Belt, Balsas Basin, and Sierra Madre del Sur provinces, all of them from central Mexico.
The ancestral area for Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana) was inconclusive, probably because of the large distribution of Al. (Az.) minuta, which is the species with largest distribution in the genus, from provinces of the central Mexican region to those in the southwestern U.S.A: Mohavian, Navahonian, Sonoran, Sierra Madre Occidental, Chihuahuan, Transmexican Volcanic Belt, and Sierra Madre del Sur. Alena (Az.) tenochtitlana, and Al. (Az.) australis are sympatric in the Baja Californian province, and share this province as their possible ancestral area.
The genus Alena was considered for a long time the sister group of the remaining extant Raphidiidae by several studies (H.
Based on our results, Alena is a monophyletic genus with several autapomorphies. Despite in our analysis this genus is supported by 16 autapomorphies, only five – all of them related to male genitalia – are exclusively to Alena. (1) Alena males have the tergite and sternite of the ninth abdominal segment separated, instead of forming a ring as in the other Raphidioptera representatives. The other two orders of insects closely related to Raphidioptera, i.e. Megaloptera and Neuroptera, also possess the ninth segment of the abdomen with separated tergite and sternite (U. Aspöck and H. Aspöck 2008), but these sclerites compounding a ring represent an autapomorphic character to Raphidioptera (
Concerning the other 11 autamorphies of Alena, two are related to wing venation and nine are related to male genitalia. Although all of these characters are present in some degree in other Raphidioptera groups, they remain of great importance for understanding the genus morphology. Most of Alena species have the presence of the apical vein on pterostigma – which probably is a modification of the RA apex –, however Al. (Az.) michoacana, and the clade Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana) secondarily lacks such vein; the presence of this vein is considered an autapomorphy of Alena, but it is also present in other species of Raphidiidae, e.g. Atlantoraphidia maculicollis (Stephens, 1836), and Ohmella postulata (H. Aspöck and U. Aspöck, 1977). Another characteristic related to wing venation and considered an autapomorphy of Alena is the second ra-rp crossvein of forewing located on the median region of the pterostigma, but Al. (Az.) michoacana and the clade Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana) have this crossvein located apically to pterostigma. It is interesting to note that only the species of Alena with apical vein have the second ra-rp crossvein located in the median region of pterostigma, whereas the species which lack the apical vein possess this crossvein located apically on pterostigma. The location of the second ra-rp crossvein on forewing is variable in other Raphidioptera species, although there is a tendency for this crossvein to be apical to the pterostigma; contrary to what is observed in Alena, this crossvein can be located in the median (e.g. Mongoloraphidia tshimganica (H. Aspöck, U. Aspöck and Martynova, 1968), see fig. 254 of H.
All Alena species have the male sternite VIII in lateral view, shorter than tergite VIII, which reaches at most 1/3 of the tergite length in the two sister species Al. (Az.) australis and Al. (Az.) tenochtitlana; this character is variable between Raphidioptera groups. The presence of the dorsal median suture on the tergite IX is also autapomorphic to Alena, with secondary loss in Al. (Az.) minuta, and Al. (Az.) caudata + Al. (Az.) infundibulata. The male gx IX have a distinct basal sclerite, and despite the clear presence of this structure is herein considered as an autapomorphy of Alena, it is actually considered synapomorphic for the clade Alena + Palearctic Raphidiidae by
An important structure, with several significant characteristics, of Alena is the ectoproct. Most species of the genus have the ectoproct rectangular in dorsal view, and subtriangular in lateral view, with a median V-shaped incision on the posterior margin, and lacking trichobothria. The exceptions are as follows: Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana), which have the ectoproct trapezoidal – with anterior margin narrower than posterior margin – in dorsal view, arm-like (elongate and narrow) in lateral view, and with posterior margin convex; Al. (Al.) distincta having a C-shaped ectoproct, in lateral view, with its apex ventrally folded; and Al. (Az.) horstaspoecki and Al. (Az.) schremmeri, which have trichobothria, considered a reversion in our analysis.
Regarding the three Alena subgenera, the monotypic Mexicoraphidia and Alena s.s. are recovered herein as sister groups, comprising a clade sister to the monophyletic Aztekoraphidia, confirming the hypothesis about their relationships presented by H.
Based on our phylogenetic analysis, Alena s.s. and Mexicoraphidia could be considered as parts of one subgenus, but we decided to maintain them as two monotypic subgenera established in other differences. Alena (Al.) distincta, the only species of the subgenus Alena s.s., has the base of MA on the hind wing as an oblique vein, whereas the only species of Mexicoraphidia – Al. (Mx.) americana – possesses this vein as longitudinal. The male of Al. (Al.) distincta has the sternite IX indistinct, the gph IX with divergent apex, and a C-shaped ectoproct (in lateral view), with an apex ventrally folded, whereas the male of Al. (Mx.) americana has the sternite IX distinct, the gph IX with parallel apex, and a subtriangular ectoproct in lateral view. Apart from the differences related to the glandulae receptaculi mentioned above, the females of both subgenera have other important differences. Whereas females of Alena s.s. have the tergite VIII ventrally separated, with its base narrower than its median region (in lateral view), those of Mexicoraphidia have the tergite VIII with a strong extension ventrally, with its base larger than its median region (in lateral view).
Alena (Az.) alanae sp. nov. is a remarkable species of Aztekoraphidia, and it is considered as sister to the remaining species of the subgenus. Despite this species shares several characteristics – mentioned above – with the other species of Aztekoraphidia, Al. (Az.) alanae is easily separated from them by the male gst IX and apex of gph IX. This new species has a large and subquadrangular gst IX, with a large base, whereas the remaining species of Aztekoraphidia have arm-like gst IX, with a narrow base. It is important to highlight that the gst IX of the new species is subquadrangular, but it is much longer when compared to those of Mexicoraphidia and Alena s.s. H.
The remaining eight species of Aztekoraphidia are recovered in three small clades. In its original description made by U. Aspöck and H. Aspöck (2013), Al. (Az.) michoacana was not related to any other species. Nevertheless, this species is herein deemed as closely related to Al. (Az.) horstaspoecki, sharing several characters among which we can highlight males with ridge of gst IX poorly-developed (well developed in other Alena species), gph IX with apex before the tergite IX apex in lateral view (apex located beyond the tergite IX apex in other Alena species), and complex of gx X located apically to gph IX as a clearly separated structure (also present in Al. (Az.) tenochtitlana, and completely amalgamated with gph IX in other Alena species), with projections (absent in other Alena species).
The second clade of Aztekoraphidia is composed of Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana). In the original description made by U. Aspöck and H. Aspöck (1978), Al. (Az.) tenochtitlana was considered closely related to Al. (Az.) australis, which is confirmed by our results. Herein, is the first time that the Al. (Az.) minuta is clearly related to other species. These three species share several synapomorphies, including the basal third of male gx IX elongate (short in other Alena species), approximately 1/2 as wide as its median region (approximately 2/3 as wide as its median region in other Alena species), and ectoproct trapezoidal in dorsal view (rectangular in other Alena species), and arm-like in lateral view (subtriangular or C-shaped in other Alena species), with median region of posterior margin convex (with V-shaped incision on other Alena species).
The third clade of Aztekoraphidia, which is sister to the group noted above, is composed of Al. (Az.) schremmeri + (Al. (Az.) caudata + Al. (Az.) infundibulata). This is not a surprise, as since the original description of Al. (Az.) schremmeri and Al. (Az.) infundibulata made by U.
The genus Alena is closely related to mountainous regions, and its species are recorded in high altitudes of provinces belonging to: (1) the Western subregion, which is composed of the Californian and Rocky mountain dominions, representing the western coastal and western central regions of southwest of U.S.A., respectively (
Apart from Al. (Al.) distincta and Al. (Az.) minuta, which also occur in the southwestern region of the U.S.A. – in the states of California, Arizona, Colorado, New Mexico, and Utah –, Alena species are present in restricted mountainous areas from western Mexico (Fig.
North American snakeflies occur only in the western region of this subcontinent, which according to U.
Alena species are also known only from the western region of North America, nevertheless this distribution is probably related to the low expansion capacity of these insects preventing their dispersion, plus the high mountain systems present in this subcontinent acting as a geographic barrier and the necessity for low temperatures for its correct development.
At present, in its northernmost portion, the eastern limit of Alena’s distribution is essentially the Rocky Mountains, which is connected to the Sierra Madre Occidental (the western limit of Alena in Mexico) in its southern portion. In the Mexican area, the eastern limit of Alena is the western part of the Mexican Plateau, the Sierra Madre Oriental, the Transmexican Volcanic Belt, the Sierra Norte de Oaxaca, and south of the Sierra Madre del Sur. All these mountains are connected and form a large barrier to Alena species in its eastern limit. The southeast part of the Mexican Plateau has connection to the Sierra Madre Oriental, which is connected in its southern region to the Transmexican Volcanic Belt – a mountain range which crosses the country in an east-west direction, approximately between the parallels of 19 and 21° N (
The western limits for Alena, from north to south, are composed of the Coastal Range Mountains, and the Sierra Nevada, which connect to the Cordillera of Baja California in the Baja California Peninsula. The western limit of the genus in the remaining Mexico is the Sierra Madre Occidental, which is connected to the Rocky Mountains in the northern part, and in the southern part with the Transmexican Volcanic Belt, which has its western part connected to the Sierra Madre del Sur (
U.
Alena is the Raphidiidae group closest to the tropical region in distribution, and although their species are present in provinces considered as part of the Mexican Transition or Neotropical Zones, this genus also needs a cool period (winter) for proper development, and occurs only in high altitudes where the temperatures are low. Nowadays, Mexican Alena species represent a snakefly fauna “imprisoned” in its former glacial refuge areas. According to this hypothesis, Alena species could extend their distribution to and in lower lands during the glacial periods, nevertheless in interglacial periods (including to date), the lower elevations lack Alena species when the rise of temperature began. This probably occurred during the Pleistocene, which is considered a series of glacial periods interposed by interglacial ones that began 2.58 Ma, and strongly affected North America, among other northern regions of the planet (
All the main lineages of Alena have some affiliation with the Transmexican Volcanic Belt, the Sierra Madre del Sur, and the Balsas Basin provinces, which are biogeographically related and share a great amount of species with one other (
The Transmexican Volcanic Belt province corresponds to the mountainous system of the Transmexican Volcanic Belt, a set of mountain ranges of volcanoes that crosses the country from west to east, and have a complex geological history and biotic connections to other biogeographic provinces resulting in one of the most complex and heterogenous Mexican provinces, with two well-defined subprovinces (
The genus Alena possesses two main lineages, the smallest of them is composed of two disjunctively distributed monotypic subgenera, Mexicoraphidia, recorded in central Mexico (provinces of the Transmexican Volcanic Belt and the Balsas Basin), and Alena s.s., located in the southwestern U.S.A. (Californian province). Although the biogeographic pattern of this clade is unclear, it is possible to assume based on our biogeographic analysis that its stem species was probably present in a large area of distribution – similar to the stem species of the genus Alena – and a vicariance event resulted in this disjunctive pattern. The second lineage of Alena is composed of Aztekoraphidia species with its stem species associated with the Transmexican Volcanic Belt, the Balsas Basin, and the Sierra Madre del Sur provinces, in central Mexico. Possibly, the changes of the distribution of Alena populations in glacial and interglacial periods provided the separation of the stem species of Aztekoraphidia from the stem species of Alena s.s. + Mexicoraphidia by dispersal and extinction events, as highlighted in our analysis.
Alena (Az.) alanae sp. nov., sister to other Aztekoraphidia, occurs in the Upper Balsas District located in the eastern area of the Balsas Basin province, and presents the higher altitudes of it, as well as a higher proportion of temperate climate species (
The group composed of Aztekoraphidia minus Al. (Az.) alanae sp. nov possesses two lineages. The smaller of them is composed of Al. (Az.) horstaspoecki and Al. (Az.) michoacana occurring in the Transmexican Volcanic Belt province and sharing a biogeographic ancestral area in this same locality. Nevertheless, the former species (Al. (Az.) horstaspoecki) is recorded to the east subprovince (areas between 2000 and 3000 m, vegetation of Pine-Encino and xerophytic scrub forests), whereas the latter species (Al. (Az.) michoacana) is present in the west subprovince (areas lower than 2000 m, deciduous tropical forests) (
The biogeographic ancestral area of Al. (Az.) minuta + (Al. (Az.) tenochtitlana + Al. (Az.) australis) was recovered as inconclusive. Alena (Az.) minuta is a highly variable species with wide distribution, occurring in several southern and northern provinces. Alena (Az.) tenochtitlana and Al. (Az.) australis are sympatric in the Baja Californian province, sharing a biogeographic ancestral area in this same locality. Our S-DIVA analysis recovered five dispersal events of the stem species of Al. (Az.) minuta + (Al. (Az.) tenochtitlana + Al. (Az.) australis) resulting in its presence in eight provinces, and a posterior vicariance event separating Al. (Az.) minuta from the stem species of Alena (Az.) tenochtitlana and Al. (Az.) australis of the Baja Californian province. Such events, similar to that from the Alena (Az.) alanae sp. nov. and the stem species of other Aztekoraphidia, also can be explained by the variation of temperature provided by the glacial and interglacial periods.
Alena (Az.) schremmeri + (Al. (Az.) infundibulata + Al. (Az.) caudata) have their biogeographical history closely related to the provinces of the central Mexican region, i.e. the Transmexican Volcanic Belt, the Balsas Basin, and the Sierra Madre del Sur. The stem species of the clade probably was present in these three provinces, and posteriorly Al. (Az.) schremmeri (currently located in the occidental subprovince sensu
Lastly, we want to connect the present analyses with previous approaches concerning the biogeography of Alena based on the concept of de Lattin (1967). This master work published in German has largely been overlooked in biogeographic circles of English-speaking authors (see U. Aspöck et al. 1992), although the “Zones” favored by
The huge Mexican glacial refuge center in the sense of de Lattin (1967), extended by H.
The distribution areas of Mexican snakeflies are still poorly known (Fig.
The structuring of the huge Mexican glacial refuge center into sub-centers deduced from the records of single species and characterizing these species as faunal elements of these sub-centers, has been a challenge from the very beginning of our studies on Mexican snakeflies (U. Aspöck and H. Aspöck 1970; U.
In addition to its uncommon morphology, Alena also has a remarkable biology, differing from other Raphidiidae species. This genus possesses larvae that pupate in the summer and autumn, and develop to imagos (about within two weeks) also in these periods, whereas the most part of other Raphidiidae genera have its larvae pupating in spring after hibernation of the last instar (H.
The known larvae of Alena are considered to be corticolous, developing under bark of trees, feeding on a great variety of soft-bodied arthropods; while the adults’ food is similar to all other Raphidiidae genera, and is especially composed of insects with preference for aphids and other Sternorrhyncha, but also predating other arthropods, and occasionally feeding on pollen (H.
Representatives of Alena are found in high areas, between 900 and 2970 m, and occur especially in Calliandra, cypresses trees, and especially in pine-oak forests, particularly in species of Arctostaphylos, Juniperus, Pinus, Quercus (H.
The genus Alena is monophyletic, as well as its subgenus Aztekoraphidia, which is sister of a clade composed of the other two monotypic genera, Alena s.s. and Mexicoraphidia. This genus has a biogeographic history strongly associated with central Mexico, especially the mountains of the Transmexican Volcanic Belt, the Balsas Basin, and the Sierra Madre del Sur provinces. Probably the stem species of the genus was originally (in preglacial periods) distributed across the central and southern regions of western North America. Its current diversity is only composed of small groups that survived imprisoned in their former glacial refuge areas in the mountains from central and western Mexico, and southwestern U.S.A. Nevertheless, the recent finding of the new Mexican species – Al. (Az.) alanae sp. nov. – demonstrates that the knowledge on actual diversity of Alena remains incomplete.
The authors have declared that no competing interests exist.
We would like to thank the administrative curator of CNIN-IBUNAM, Cristy Mayorga, for the support in the curation of all Neuropterida material, as well as supplying several species of Mexican snakeflies. We are thankful to our friends Luis Fernando Villagomez, who collected and made the specimens of the new species available to us; Adrian Ardila-Camacho, who provided the pictures of specimens; Alana C. D. Brunini for the support in curation of the snakeflies biological material; and editor Ricardo Pérez-de la Fuente plus an anonymous reviewer for critical comments that greatly improved the manuscript. CCM acknowledges Programa de Becas Posdoctorales DGAPA-UNAM 2019-2021 for a postdoctoral fellowship. CCM and ACR thank projects “Biodiversidad de Neuroptera en México: un enfoque taxonómico integrativo” (CONACYT CB2017-2018 A1-S-32693) and “Biodiversidad de grupos selectos de Neuropteroidea de la Península de Baja California” (PAPIIT-UNAM IN209721) for general support.
List of characters (coded in Table
Wings
1. Color of pterostigma: (0) one color (usually brown or yellow); (1) two colors (usually with brownish base and yellowish apex).
Pterostigma color is also variable in Neuropterida, however it is constant in each species of Alena, what enabled its use as a reliable character in our analysis. Most of the Alena species possess the plesiomorphic state, pterostigma with one color, while this region with two colors is synapomorphic to Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana), and has an independent origin in Ag. (Ag.) bicolor.
2. Apical vein: (0) absent; (1) present.
Apical vein is an oblique vein located at the apical region of pterostigma and is present in some representatives of Raphidiidae, including most part of Alena. Its presence is considered an autapomorphy of the genus, with two independent secondary losses, in Al. (Az.) michoacana and Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana).
3. Second ra-rp crossvein on forewing: (0) on the base of pterostigma; (1) apically to pterostigma; (2) on the median region of pterostigma.
The location of the forewing second ra-rp crossvein is also variable in Raphidioptera. The presence of this crossvein on the median region of pterostigma is considered autapomorphic to Alena, with two independent displacements to the most apical region of pterostigma in Al. (Az.) michoacana, and Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana), also present in Ag. (Ag.) bicolor.
4. Base of MA on hind wing: (0) absent; (1) as cross or oblique vein; (2) as longitudinal vein.
Indianoinocellia mayana has no visible base of MA on the hind wings, so its presence is synapomorphic to the remaining species of the analysis. Hind wing with base of MA as cross/ oblique vein is synapomorphic to Ag. (Ag.) bicolor and Alena, while MA base as longitudinal vein is present in Al. (Mx.) americana, Al. (Az.) horstaspoecki, and Al. (Az.) schremmeri + (Al. (Az.) caudata + Al. (Az.) infundibulata).
Male abdomen and genitalia
5. Sternite VIII length, lateral view: (0) as long as tergite VIII; (1) 3/4–1/2 of the tergite VIII length; (2) 1/3 of the tergite VIII length.
Despite the length of the sternite VIII is variable among Raphidiidae genera, a shorter male sternite VIII is synapomorphic to Alena representatives, with Al. (Az.) australis and Al. (Az.) tenochtitlana sharing an even more extreme condition of this state, i.e. sternite VIII length corresponding to 1/3 of the tergite VIII length.
6. Tergite and sternite of segment IX: (0) forming a ring; (1) separated.
Male sclerites of ninth abdominal segment forming a ring is autapomorphic to Raphidioptera (
7. Tergite IX, dorsal view: (0) without median suture; (1) with median suture.
Most Alena species have a median suture in the dorsal region of male tergite IX, herein considered autapomorphic to the genus. Alena (Az.) minuta, and Al. (Az.) caudata + Al. (Az.) infundibulata have independently secondary losses of such suture.
8. Sternite IX: (0) distinct; (1) indistinct.
The plesiomorphic state is widely distributed in the Alena lineages. The apomorphic state originated four times: Al. (Al.) distincta, Al. (Az.) michoacana + Al. (Az.) hostaspoecki, Al. (Az.) australis + Al. (Az.) tenochtitlana, and Al. (Az.) caudata.
9. Basal sclerites of gx IX: (0) amalgamated; (1) distinct.
Agulla species have males with no basal sclerites, which is apomorphic or plesiomorphic depending from the hypothesis of Raphidiidae phylogenetic relationships (
10. Shape of gx IX (length/width): (0) gx IX wider than long; (1) gx IX 1.2–1.5× longer than wide; (2) gx IX at least 1.7× longer than wider.
The length of gx IX was measured as the distance between its base and the base of its apex, and the width was measured in the median region of gx IX.
The ratio between length and width of gx IX varies between Raphidioptera species, but Alena species have this structure elongated on the longitudinal axis, at least 1.2× longer than wide. In the species Al. (Az.) schremmeri, Al. (Az.) caudata, Al. (Az.) infundibulata, Al. (Az.) minuta, Al. (Az.) australis, and Al. (Az.) tenochtitlana this elongation is even more remarkable, with gx IX at least 1.7× longer than wide.
11. Width of basal third of gx IX: (0) wider than the median region of gx IX; (1) approximately 2/3 as wide as the median region of gx IX; (2) approximately 1/2 as wide as the median region of gx IX.
Male gx IX with basal third narrower than its median region is autapomorphic to Alena. In Al. (Az.) minuta, Al. (Az.) australis, and Al. (Az.) tenochtitlana it is more emphasized, with the basal third having 1/2 of the median region of gx IX.
12. Length of basal third of gx IX: (0) short; (1) elongated.
The elongation of the basal third of male gx IX clearly occurred once in the Alena evolutionary history, with the apomorphic state being a synapomorphy of the clade composed of Al. (Az.) minuta, Al. (Az.). australis, and Al. (Az.) tenochtitlana.
13. Ventral margin of gx IX: (0) slightly convex or straight; (1) concave on median region.
Alena (Az.) australis and Al. (Az.) tenochtitlana possess the ventral margin of male gx IX slightly curved up, resulting in a concave median region, synapomorphic to this clade.
14. Apex of gx IX: (0) absent; (1) located below or before the gst IX base; (2) located above or in front of gst IX.
All the male Alena species have the gx IX with a distinct apex. It can be located below or before the gst IX base, synapomorphic to Alena s.s. + Mexicoraphidia, or located above or in front of gst IX, autapomorphy of Aztekoraphidia.
15. Apex of gx IX (when present): (0) short, and digitiform; (1) elongated, and arm-like or rod-shaped.
The apomorphic state originated independently twice, in Al. (Az.) minuta, and synapomorphic to Al. (Az.) schremmeri + (Al. (Az.) caudata + Al. (Az.) infundibulata).
16. Dorsoposterior tapered process of gx IX: (0) absent; (1) present, not serrated; (2) present, serrated.
The presence of the dorsoposterior tapered process on male gx IX is synapomorphic to Al. (Az.) schremmeri + (Al. (Az.) caudata + Al. (Az.) infundibulata). Different from the other two species, males of Al. (Az.) infundibulata have the dorsal margins of such process serrated. Some of the Al. (Az.) minuta males possess this process, while others not, so this species was coded as missing data “?”.
17. Ridge of gst IX: (0) absent; (1) well developed, elongate; (2) poorly developed.
The ridge of male gst IX is a sclerotized region of the gx IX which serves as insertion point to gst IX muscles, it is located at the base of gst IX, and is easily observed in Raphidiidae representatives (H.
18. Shape of gst IX: (0) subtriangular; (1) subquadrangular; (2) arm-like, elongated.
The outgroup males utilized in our analysis have a subtriangular gst IX. The subquadrangular gst IX was recovered as an autapomorphy of Alena, however it is only present in Al. (Al.) distincta, Al. (Mx.) americana, and Al. (Az.) alanae sp. nov. The remaining species of Alena share an arm-like gst IX as synapomorphy, characteristic already considered as autapomorphy of Aztekoraphidia by H.
19. Shape of base of gst IX, lateral view: (0) large, approximately two times as large as its apex; (1) narrow, approximately as large as its apex.
Males with large base of gst IX are present in Al. (Al.) distincta, Al. (Mx.) americana, and Al. (Az.) alanae sp. nov., while the remaining species of Alena shares gst IX with narrow base.
20. Apex of gst IX: (0) simple; (1) bifurcated.
Most Raphidiidae species, including all Aztekoraphidia, have males with simple gst IX apex. The other two subgenera of Alena, i.e. Alena s.s. and Mexicoraphidia, share male gst IX with bifurcated apex, synapomorphy of this clade.
21. Gph IX: (0) composing paired short structures (“pseudostyli”); (1) composing a structure with two elongated rods (“hypovalva”).
According with U. Aspöck and H. Aspöck (2004), the male gonapophyses IX composing the “hypovalva” is autapomorphic to Raphidiinae. In our analysis, this characteristic is synapomorphic to Agulla and Alena, with I. mayana presenting the plesiomorphic state.
22. Position of gph IX apex (when composing the “hypovalva”), lateral view: (0) located beyond the tergite IX apex (generally reaching at least 3/4 of gx IX length); (1) located before the tergite IX apex (generally reaching 1/4-1/2 of gx IX length).
This character is contingent on (or associated with) presence of gph IX composing a structure with two elongate rods (“hypovalva”) in males, and it is better observed in lateral view. Indianoinocellia mayana has no “hypovalva”, so it is coded as inapplicable “-“. Agulla (Ag.) bicolor, and most part of Alena, have males with gph IX apex surpassing the tergite IX apex, while Al. (Az.) michoacana and Al. (Az.) horstaspoecki share male gph IX with its apex not reaching the tergite IX apex.
23. Arrangement of gph IX apex (when composing the “hypovalva”), ventral view: (0) parallel; (1) divergent.
This character is contingent on (or associated with) the presence of gph IX composing a structure with two elongated rods (“hypovalva”) in males, and it is better observed in ventral view. Indianoinocellia mayana has no “hypovalva”, so it is coded as inapplicable “-“. The arrangement of the apex of male gph IX is highly variable between the groups of Raphidiidae, including species of Alena. The apomorphic state has two independent origins, in Al. (Al.) distincta, and in the clade composed of Aztekoraphidia minus Al. (Az.) alanae sp. nov., which have a reversion to gph IX apex parallel in Al. (Az.) schremmeri.
24. Shape of gph IX apex (when composing the “hypovalva”), ventral view: (0) rhomboid; (1) tapered.
This character is contingent on (or associated with) the presence of gph IX composing a structure with two elongated rods (“hypovalva”) in males, and it is better observed in ventral view. Indianoinocellia mayana has no “hypovalva” so it is coded as inapplicable “-“. Similar to character 23, it is highly variable in Raphidiidae, nevertheless most species of Alena have male gph IX with a tapered apex, which was recovered as autapomorphic to the genus. Two reversions to rhomboid apex occurred independently, in Al. (Az.) schremmeri and Al. (Az.) michoacana + Al. (Az.) horstaspoecki.
25. Gph IX (when composing the “hypovalva”), ventral view: (0) weakly or not inserted on the basal sclerites of gx IX; (1) broadly inserted on the basal sclerites of gx IX.
This character is contingent on (or associated with) the presence of gph IX composing a structure with two elongate rods (“hypovalva”) in males, and it is better observed in ventral view. Indianoinocellia mayana has no “hypovalva”, so it is coded as inapplicable “-“. Males with gph IX strongly inserted in the basal sclerites of gx IX is autapomorphic to Alena, highlighted by
26. Complex of gx X: (0) located at the base level or laterally to gph IX; (1) completely amalgamated with gph IX; (2) located apically to gph IX.
Males with the complex of gx X located at the base or laterally to gph IX are present in I. mayana and Ag. (Ag.) bicolor, and this is considered the plesiomorphic state in our analysis. U.
27. Projections of complex of gx X (when not amalgamate with gph IX): (0) absent; (1) present.
This character is contingent on presence of complex of gx X separated from gph IX in males. Alena (Az.) tenochtitlana has the plesiomorphic state, while the presence of projections is synapomorphic to Al. (Az.) horstaspoecki + Al. (Az.) michoacana. All the other species of Alena have the complex of gx X amalgamated with gph IX, so there are coded as inapplicable “–” for these.
28. Shape of ectoproct, dorsal view: (0) subquadrangular; (1) rectangular; (2) trapezoidal, with anterior margin narrower than posterior margin.
Males of I. mayana and Ag. (Ag.) bicolor have subquadrangular ectoprocts. Most species of Alena present males with rectangular ectoprocts, elongate in antero-posterior axis, and considered autapomorphic to the genus. The change to trapezoidal ectoproct, with anterior margin narrower than its posterior margin, is synapomorphic to Al. (Az.) minuta + Al. (Az.) australis + Al. (Az.) tenochtitlana).
29. Shape of median region of ectoproct posterior margin, dorsal view: (0) approximately straight; (1) with median V-shaped incision; (2) convex.
Indianoinocellia mayana and Ag. (Ag.) bicolor have the male ectoproct with posterior margin approximately straight, while the male ectoproct with a median V-shaped incision on its posterior margin is autapomorphic to Alena. Nevertheless, the clade Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana) have the median posterior margin of the ectoproct convex, clearly synapomorphic to this group.
30. Shape of ectoproct, lateral view: (0) rounded or subquadrangular; (1) subtriangular; (2) C-shaped, with apex ventrally folded; (3) arm-like.
The lateral shape of the male ectoproct is also highly variable in Raphidioptera. Herein the rounded or subquadrangular ectoprocts on males are considered the plesiomorphic state, present in outgroups. Subtriangular ectoproct is synapomorphic to Alena species, suffering two changes: (1) C-shaped ectoproct in Al. (Al.) distincta, and (2) arm-like ectoproct, elongate and narrow in lateral view, in Al. (Az.) minuta + (Al. (Az.) australis + Al. (Az.) tenochtitlana).
31. Trichobothria on ectoproct: (0) present; (1) reduced or absent.
Most part of the Neuropterida groups have trichobothria in its male ectoprocts, nevertheless their amount, presence/absence, and distribution are variable. Indianoinocellia mayana and Ag. (Ag.) bicolor clearly possess trichobothria. Most part of Alena species have male ectoprocts without trichobothria or in small number, which is autapomorphic to the genus. Two distant species of Aztekoraphidia, Al. (Az.) horstaspoecki and Al. (Az.) schremmeri, possess males with ectoprocts bearing trichobothria, which is considered two independent reversions.
Female abdomen and genitalia
As Alena (Az.) michoacana has no described female, it is coded as missing data “?” in the following characters of female.
32. Tergite VIII: (0) ventrally separated, not forming a ring; (1) with strong ventral extension; (2) fused ventrally, forming a ring.
Generally, the tergite VIII of females is ventrally separated in snakeflies, which is also observable on most part of Alena. However, Al. (Mx.) americana has its tergite VIII with a strong extension, which is considered its autapomorphy. Other important apomorphic state was originated inside the Aztekoraphidia subgenus, with Al. (Az.) australis + Al. (Az.) tenochtitlana possessing females with tergite VIII ventrally fused, forming a ring.
33. Tergite VIII, lateral view: (0) base narrower than, or as large as, its median region; (1) base clearly larger than its median region.
Character highly variable in Raphidioptera. Most part of Alena species have females possessing the plesiomorphic state, but there are three independently origins of the female tergite VIII, having its base clearly larger than its median region, in Al. (Mx.) americana, Al. (Az.) australis + Al. (Az.) tenochtitlana, and Al. (Az.) infundibulata; state also present in Ag. (Ag.) bicolor.
34. Atrium bursae: (0) inconspicuous; (1) large, robust; (2) tube-like.
The atrium bursae of I. mayana females is inconspicuous. Large and robust atrium bursae is herein synapomorphic to Agulla and Alena, while females possessing this structure tube-like is clearly an autapomorphy of Aztekoraphidia.
35. Receptaculum seminis: (0) not adhered to the atrium bursae; (1) adhered or fused with the atrium bursae; (2) absent or strong reduced.
Females with receptaculum seminis not adhered to the atrium bursae are present in the outgroups, and suffered two different changes in Alena: (1) receptaculum seminis strongly reduced or absent in Al. (Al.) distincta + Al. (Mx.) americana; (2) adhered or fused with atrium bursae in Aztekoraphidia.
36. Glandulae receptaculi: (0) short; (1) elongate; (2) inconspicuous.
Short glandulae receptaculi in females are considered as the plesiomorphic state, present in I. mayana, Ag. (Ag.) bicolor, and Al. (Mx.) americana. Inconspicuous glandulae receptaculi represent an autapomorphy of Al. (Al.) distincta, while elongated glandulae receptaculi are autapomorphic to Aztekoraphidia species.