Psomizopelma brachypterum Gibson 1995

Psomizopelma brachypterum Gibson

Figs 17–31

Psomizopelma brachypterum Gibson, 1995: 258 –259.

Material examined. USA. Florida. Monroe Co., Fat Deer Key, 4.III-28.IV. 1 985 (allotype ♂ CNC), 4.V- 4.VIII.1985 (1♀ PT CNC), 4.VI.1986 (1♀ PT CNC, CNC Photo 2017-20), S.&J. Peck, hammock forest, MT & FIT. Big Torch Key, SW1/4, Sec. 12, 4.III-29.IV.1985, S.&J. Peck, hammock forest, MT & FIT (1♂ PT CNC). N. Key Largo, Sec. 35, [no date] (4♂ PT CNC, CNC Photos 2017-22, 2017-23, 2017-25; 1♂ PT USNM), 1.VIII- 16.XI.1985 (1♂ PT CNC), S.&J. Peck, hammock forest, MT-FIT. No Name Key, 23.II-3.VI.1986, S.&J. Peck, hammock forest, malaise & FIT (holotype ♀ CNC; 1♀ PT USNM, CNC Photo 2017-21); 1.VI.1986, M. Kaulbars (1♀ PT CNC).

Description. FEMALE (habitus: Figs 17, 18). Length about 2.6–3.1 mm. Head (Figs 17–20) mostly brown to dark brown but clypeus and lower face lateral of clypeus to about level of inner or outer margin of torulus distinctly paler, more brownish-yellow (Fig. 20). Labiomaxillary complex with palps dark brown (Fig. 20). Antenna (Fig. 17) uniformly dark brown or sometimes scape and sometimes also pedicel and basal funiculars somewhat paler, lighter brown to brownish-yellow, but with whitish setae. Mesosoma (Figs 17, 18, 21) dark brown except for following: pronotal panel with ventral and posterolateral margins whitish (Fig. 21), mesopectus ventrally at least anterior of mesocoxae and acropleuron posteroventrally above mesocoxa (Fig. 21) obviously paler, brownish-yellow, and mesopectus sometimes more extensively pale on either side of discrimen. Legs (Figs 17, 18) similarly dark as mesosoma except meso- and metafemora variably distinctly paler, more similar in color to paler parts of mesopectus and acropleuron. Gaster dark brown except Gt1–Gt3 laterally and all sternites except for hypopygium white (Figs 18, 24), and ovipositor sheaths yellow (Fig. 24) or at least distinctly paler, brownish-yellow apically.

Head with face (Fig. 19) almost uniformly punctate-reticulate and completely setose except scrobes above toruli and often interantennal prominence mesally; eyes and face with white hairlike or at most very slender, elongate-lanceolate setae except for brownish hairlike setae on clypeus and lower face lateral of clypeus; scrobal depression comparatively shallow and small, delimiting broad parascrobal region (Figs 19, 20), minimum width of parascrobal region between torulus and lower inner orbit at least as wide as torulus and about 0.5× distance between toruli; malar space about 0.33× eye height; OOL: POL: LOL: MPOD = 28: 29: 18: 10; interorbital distance about 0.5× head width. Antenna with scape comparatively slender, about 5× as long as greatest width, with ventral margin almost straight so subequal in width over most of length though slightly narrower basally; clava about at long as combined length of apical 6 funiculars.

Brachypterous (Figs 17, 23, 24); fore wing about 5× as long as maximum width and extending only to about base of gaster (Figs 17, 23), at most slightly beyond level of petiole; orangish-brown with dense lanceolate setae over both membrane and venation, basally and sometimes subapically the setae darker brown, but at least with more orangish setae in band near middle and apically, and sometimes more uniformly orangish over about apical half to two-thirds. Mesonotum (Fig. 17) similarly punctate-reticulate as head, with dark setae; scutellum (Fig. 23) conspicuously elongate-slender, at least twice as long as wide and 1.3× maximum width of scutellar-axillar complex. Prepectus bare (Fig. 21). Acropleuron (Figs 21, 22) isodiametric reticulate anteriorly and posteriorly, though reticulations smaller posteriorly, and with much smaller punctate-reticulate sculpture just beyond setae. Metapleuron (Fig. 22: pl3) bare dorsal to transverse carina delimiting setose metasternum (Fig. 22: st3). Front leg with femur (cf. Fig. 37) strongly expanded over about apical half such that ventral margin conspicuously sinuate and dorsal length at most about 3× maximum width; tibia also conspicuously compressed such that at most about 4× as long as maximum width at midlength. Hind leg (Fig. 18) with coxa distinctly setose dorsobasally and ventrolongitudinally as well as across outer surface over almost apical half; femur quite obviously expanded apically, the enlarged region delimited basally by distinct notch on dorsal margin; tibia conspicuously compressed and with distinct notch near midlength so dorsal margin convex basally and apically; basitarsomere very slightly, inconspicuously compressed. Propodeum with foramen sinuately incurved to anterior margin.

Metasoma with petiole obviously transverse, lunate. Gaster dorsally (Figs 17, 24) more or less uniformly meshlike reticulate; Gt1 mostly bare dorsally, but Gt2 and subsequent tergites densely setose with posteriorly directed setae, the setae dark dorsally but paler, more whitish laterally.

MALE (habitus: Figs 25, 26). Length about 1.8–2.3 mm. Head (Figs 25–27) brown to dark brown with interantennal prominence and lower face at most slightly paler and with at most slight, obscure metallic bluish to purplish lusters. Labiomaxillary complex with palps brown. Antenna (Fig. 28) entirely brown. Mesosoma (Figs 25, 26, 30) entirely, similarly brown to dark brown as head except ventral margin of pronotal panel pale and mesoscutum sometimes with obscure metallic purple to bluish lusters. Legs entirely brown except basal two pro- and/or mesotarsomeres sometimes white (Fig. 26). Gaster similarly brown as mesosoma (Fig. 25).

Head (Fig. 27) with Π-shaped scrobal depression shallowed toward but not extending to anterior ocellus, the depression often somewhat more coarsely meshlike reticulate than frontovertex; vertex with dark setae and lower face usually with paler brown setae, but eyes, interantennal prominence, parascrobal regions, and frons between scrobal depression and anterior ocellus with whitish setae. Width of parascrobal region between torulus and lower inner orbit almost 0.4× distance between toruli; malar space about 0.4–0.45× eye height; OOL: POL: LOL: MPOD = 17: 20: 11: 10; interorbital region almost 0.6× head width. Antenna (Fig. 28) with length (width) ratio of scape: pedicel: funiculars: clava = 52(14): 22(9): 10(9), 11(10), 14(11), 14(12), 13(12), 11(12), 10(12), 9(12): 41(13); scape moderately compressed, of subequal width throughout; flagellum with most funiculars subquadrate.

Fore wing (Fig. 29) hyaline except disc behind marginal and stigmal veins brownish to about level of medial fold; relative length of cc: mv: stv: pmv = 6.2: 3.0: 1.0: 3.0. Front leg with femur apically and tibia similarly expanded and compressed as for female. Hind leg with tibia distinctly compressed, at least over apical half, only about 6.75× as long as greatest width. Metapleuron (Fig. 30: pl3) with 2–5 setae dorsal to ventral carina distinguishing much smaller metasternum (Fig. 30: st3). Propodeum bare between spiracle and median carina (Fig. 31).

Distribution. Nearctic: USA (Florida).

Remarks. No new specimens of P. brachypterum have been discovered since its original description, but the species is now known to form a species trio along with P. fuscum and P. metallicum. Females of the three species share at least four distinctive features—a mostly dark brown body (e.g. Figs 17, 18), whether or not with evident metallic luster (Figs 54, 61, 62), comparatively broad parascrobal regions in association with a relatively shallow scrobal depression (e.g. Fig. 20), white setae on the face and eyes (e.g. Fig. 19), and a conspicuously compressed profemur (apically) and protibia (e.g. Fig. 37). The discovery of another brachypterous species from Florida, P. metallicum, was unexpected, but females of P. brachypterum and P. metallicum are differentiated by both colour and sculptural features as discussed under the latter species. Currently, P. brachypterum is known only from the Florida Keys, whereas P. metallicum is known only from two eastern counties near the middle of the peninsula. As discussed under P. albiclava, males of P. brachypterum, P. fuscum and P. metallicum likely are all quite similar except P. metallicum males possibly are more distinctly metallic.