Amydrostylus triadicophallus Lamas, Falaschi & Evenhuis, sp. nov.
Creators: name: Lamas, Carlos J. E.
name: Falaschi, Rafaela L.
name: Evenhuis, Neal L.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Mythicomyiidae
Amydrostylus
Amydrostylus triadicophallus

description: Amydrostylus triadicophallus Lamas, Falaschi & Evenhuis sp. nov.
(Figs 6–7, 10–40)
Diagnosis. As for the genus.
FIGURES 6–9. Amydrostylus triadicophallus gen. nov. et sp. nov., male, paratype. 6, maculation localized on veins Sc, R1 and R2+3 (Scale bar: 0.2 mm); 7, wing (Scale bar: 0.2 mm); 8, Onchopelma nitidum, wing (not in scale, modified from Evenhuis (2002)); 9, Acridophagus sp., wing (not in scale, modified from White (1916)).
Material examined. HOLOTYPE ♂, BRAZIL, Mato Grosso do Sul, Porto Murtinho, Fazenda Retiro Conceição, 21° 41' 42.9'' S – 57° 45' 51.2'' W, Malaise 32, SISBIOTA, 26.xii.2011 – 10.i.2012, Lamas, Nihei & equipe col. (MZUSP). PARATYPES: 1 ♂ (dissected), same data as holotype (MZUSP); 1 ♂, same data as holotype, except 25.i–29.iii.2012 (MZUSP); 1 ♀ (dissected), same data as holotype, except 21°40'59.7''S 57°46'42.5''W, Malaise 31, 10–25.i. 2012 (MZUSP); 1 ♂, same data as holotype, except 21°40'59.7''S 57°46'42.5''W, Malaise 31, 10–25.i. 2012 (BPBM); 1 ♀ (SEM images), same data as holotype (BPBM).
Description. Male (Fig. 10). Measurements (n = 6): Body length: 1.9–2.3 mm. Wing: 1.0– 1.6 mm long, 0.49– 0.51 mm wide. Head (Figs 12–19). slightly (1/4) wider than long, eyes dichoptic, well separated, face bare, yellowish brown, with conspicuous oral genal cup (Fig. 13); eyes reddish throughout with dark brown margin, evenly rounded in profile; front brown to yellowish brown, widest at ocellar tubercle level, dark brown on upper corners, ocellar tubercle dark brown with 3 large yellowish brown, sub-elliptical ocelli (Fig. 15); occiput dark brown pruinose; antenna yellowish brown, entirely covered by microsetae (Fig. 14); scape short, half pedicel length, 2X wider than long; pedicel rounded, half of first flagellomere length; first flagellomere cylindrical, with sensorial pits on outer lateral surface (Fig. 16); second flagellomere digitiform, with apical depression and minute stylus (Figs 17–19). Proboscis long, surpassing oral margin by distance equivalent to head length (Fig. 12). Thorax (Fig. 20). Post pronotal lobe whitish with yellowish white setae; scutum yellowish brown, with 3 dark brown coalescent longitudinal vittae (Fig. 20) each pointed apically, with minute dark brown setae; central vitta longer than others; scutellum dark brown, with small dark brown setae. Pleura entirely bare; anepisternum yellowish white, with yellowish brown area on anterobasal corner; katepisternum yellowish brown with upper third yellowish white, lower margins dark brown; anepimeron yellowish white, with yellowish brown area on anterobasal corner; meron yellowish brown in lower half, yellowish white in upper half; laterotergite yellowish white; metepisternum yellowish brown in lower half, yellowish white in upper half. Halter stem and knob white. Wing (Figs 6–7). Elongate, length 3.2X width; hyaline, covered with microsetae, with discrete faint maculation localized on veins Sc, R1 and R2+3 (Fig. 6); veins yellowish brown, well sclerotized; C with short macrosetae, ending slightly beyond end of R4+5; vein Sc complete, ending in C; R4+5 slightly curved upward at wing margin; vein M1 straight; M2 slightly curved at wing margin; A1 slightly sinuous to wing margin; A2 almost inconspicuous; cup open at wing margin by width equal to r-m crossvein; fringe of hair on posterior margin longer near base. Alula reduced. Legs (Figs 23–28). Forecoxa dirty white, midcoxa and hindcoxa concolorous with katepisternum; femora and tibiae uniformly whitish and tarsi yellowish brown; femora, tibiae and tarsi (Figs 23, 25, 27) with fine, short, sparse white setae; tarsal claws (Figs 24, 26, 28) dark brown in apical half. Abdomen (Figs 10, 20). Tergites yellowish white, broad, membranous, with sparse light brown short macrosetae; tergite I with light brown areas laterally and irregular transversal stripe on center and on posterior margin; tergites II-VII with light brown areas laterally; dorsal longitudinal stripe of rounded light brown spots on center of all tergites; sternites membranous, whitish. Genitalia (Figs 29–35). Hypopygium light brown. Gonocoxa flattened, with central ridge (Figs 29, 30), gonostylus subtriangular (Figs 29, 33–35); aedeagal bulb rounded; aedeagus trifid, with central phallus more than 2X longer than lateral phalli (Figs 32, 34, 35); epiphallus longer than gonocoxa, with enlarged apex; aedeagal sheath subtriangular with 2 lateral arms (Fig. 31); epandrium with rounded margins, large pointed dorsolateral process and dorsal subtriangular projection (Figs 31, 34, 35). Female (Fig. 11). As in male, except distinguished by distended abdomen and lighter abdominal spots (Figs 21–22). Genitalia (Figs 36–40): vaginal furca (Figs 38, 40) curved and bracket-shaped ({), thickened, interrupted medially at vaginal orifice; spermathecal reservoir (Figs 36, 37, 39) coiled, gradually widening toward apex, sclerotized brown, ending basally in poorly sclerotized rounded valve; apical spermathecal duct (Figs 36, 39) ca. 0.5X length of spermathecal reservoir, thin, transparent; central sperm pump duct (Figs 36, 39) darker and about 2X length of lateral ones and equivalent to apical duct length; apical sclerotized collars small; basal duct (Fig. 39) confluent with sperm pump.
Remarks. All collected females have some wing damage.
Note. The knowledge of the immature stages of Mythicomyiidae flies are still very poorly known. As noted by Kirk-Spriggs & Evenhuis (2008) for Psiloderoides, the species of Amydrostylus gen. nov. also present an enlarged female abdomen, which was hypothesized by those authors as being an adaptation for the deposition of large quantities of eggs freely in the environment.
description: Published as part of Lamas, Carlos J. E., Falaschi, Rafaela L. & Evenhuis, Neal L., 2015, A new genus and species of micro bee flies from Brazil (Diptera: Mythicomyiidae: Psiloderoidinae), pp. 403-416 in Zootaxa 3955 (3) on pages 404-407, DOI: 10.11646/zootaxa.3955.3.7, http://zenodo.org/record/253459