Hydropeza unguicula, Sinclair, 2016

Sinclair, Bradley J., 2016, Revision of the Australian species of Hydropeza Sinclair (Diptera: Empididae: Ragadinae subfam. nov.), Records of the Australian Museum 68 (1), pp. 1-22 : 18-19

Hydropeza unguicula sp. nov.

Figs 6 , 18 , 21

Type material. Holotype ♂, Tasmania: “Pelion Tas/ June 1990 / INaumann”; “ HOLOTYPE / Hydropeza / unguicula/ Sinclair [red label]” (ANIC).

Diagnosis. This Tasmanian species is recognized by the modified male forelegs, especially the claw-like process of tarsomere 1 and pointed spatulate process of tarsomere 4 of the male midleg.

Description. Head, thorax and legs dark brown, abdomen slightly paler. Wing length 3.8 mm.

Male. Head. Ocellar setae long, erect, divergent, inserted between anterior and posterior ocelli; ocellar tubercle with several short setulae; postocellar and postocular setae dark, stout to slender; postgenal setae similar to postoculars. Lower half of face lacking setulae. Scape long and slender, about 2× length of globular pedicel; postpedicel elongate, basal portion not broader than pedicel, shorter than slender, tapered apical portion; stylus slightly longer than apical portion of postpedicel, concolorous with postpedicel. Proboscis stout and robust, long, extended well beyond mid-length of fore coxa, directed posteriorly; palpus about 0.75× length of proboscis, clothed in long setae, apex of palpus rounded (view of apex obscured by wing).

Thorax. Clothed in fine pruinescence; mesonotum brown; pleura paler along sutures. Setae not distinctly long or stout; 6 acrostichal setulae anterior to 1st dorsocentral seta, about 0.25× length of dc; pprn with 1 seta and one dark setula; 1 long presut spal and several finer short setulae; 5 uniserial dc, with intermixed finer setae; 3 npl; 1 long psut spal and 1–2 finer setulae; 1 pal seta; 1 pair of sctl, with 1 pair of finer outer marginal setae. Antepronotum with pair of slender setae.

Legs. Brown, increasingly darker apically. Inner anterior margin of fore coxa with more than 20 dark, short and thickened spine-like setae, mostly concentrated apically and mid-basally; apical setae longer than basal setae of coxa. Anterior surface of mid and hind coxae with long brown setae. Legs not clothed in very long setae as typical for genus. Fore femur slightly arched with long, silky ventral setae; nearly subequal to width of femur; base with pair of long, slender setae, nearly twice width of femur; distal half with distinctly separated brush of long, dark posterodorsal setae. Fore tibia slightly arched medially; posterior face with long, scattered setae, similar to fore femur; apical half with numerous, scattered, spine-like anterodorsal setae; apical half with 2 widely spaced, posteroventral spine-like setae. Fore tarsomere 1 shorter than segment 2, with long claw-like apical process directed ventrally ( Fig. 18 ); base with spinelike anteroventral seta, two-thirds length of tarsomere; apex with spine-like posteroventral, posterior and anteroventral preapical seta; claw-like process tapered and twisted to posterior face of tarsi, bearing 4 long divergent setae, longer than tarsomeres 1 and 2 combined and several stout subapical setae. Fore tarsomere 2 with 1 long radiating seta similar to long setae on claw-like process; with several stout preapical setae. Mid femur with posteroventral row of widely spaced setae, length nearly twice width of femur; basal half with 3 long ventral setae, twice width of femur; 1 anterodorsal on distal fifth; apex with 1 anterodorsal preapical seta. Mid tibia with 2 anterodorsal, 3 anteroventral and row of posteroventral setae; apex with several preapical setae. Mid tarsomere 1 lacking erect stout setae. Hind femur with 1 anterodorsal setae on apical fifth and 1 preapical anterodorsal seta. Hind tibia with 2 anterodorsal setae, 2 anteroventral setae and 1 dorsal seta on apical fourth; 1 anterodorsal and 1 anteroventral preapical seta. Hind tarsomere lacking erect stout setae. Tarsomeres of foreleg longer than tibia; ventral apical margin of tarsomere 4 of foreleg flattened and expanded; midleg tarsomere 4 expanded into pointed spatulate projection, longer than segment; tarsomere 4 of hindleg laterally compressed ventrally, keel-like, extending slightly beyond apex; tarsomere 5 of each leg lacking dorsoapical extension.

Wing. Infuscate with 1 long basal costal seta, slightly longer than sctl; all veins lacking setulae; R 4 and R 5 distinctly divergent apically; bm-m complete; cell dm slightly produced, shorter than length of cell bm; CuA + CuP absent. Halter brown.

Abdomen. Tergites and sternites clothed in setae; setae of posterior margin overlapping more than half length of following tergite.

Terminalia (undissected). Cercus divided into small, flat, horizontal dorsal lamellae surrounding anus, and slender, parallel-sided, medially arched lateral lamellae. Epandrium similar in form to lateral cercal lamella, arched medially. Hypandrium cone-shaped; postgonite not observed. Paired spine-like lobes arching from near base of phallus; phallus long and filamentous, recurved above terminalia.

Female. Unknown.

Distribution. Only the male holotype of this species is known, collected during winter (June) from Cradle Mountain National Park, Tasmania (Fig. 21).

Etymology. The specific name is from the Latin unguiculus (claw, talon), in reference to the claw-like projection from tarsomere 1 of the male foreleg.

Remarks. The male terminalia was not dissected, because only a single specimen is known. However, the highly modified forelegs should facilitate species recognition.

Figures

Figures 3–6. Habitus images of dried mounted male species of Hydropeza, lateral view. (3) H. aptera. (4) H. intricata. (5) H. tasmanica. (6) H. unguicula. Scale bars = 1.0 mm, except Fig. 3 where scale bar = 0.5 mm.

Figures 13–18. Scanning electron photographs of Hydropeza tasmanica and digital image of foreleg of H. unguicula. (13) Head (scale bar = 0.5 mm) (from Sinclair & McLellan, 2004, fig. 10). (14) Fore coxae (scale bar = 0.2 mm). (15) Male mid femur (scale bar = 0.1 mm). (16) Male mid femur and tibia (scale bar = 0.5 mm). (17) Tarsomere 5 and acropod (scale bar = 0.2 mm). (18) Male forelegs of H. unguicula (scale bar = 1.0 mm).