Empis chiragra Bezzi, 1909

Rafael, J. A. & Câmara, J. T., 2012, Revision of Neotropical species of Empididae (Diptera) described by Mario Bezzi. XI. The species described in Empis Linnaeus, Zootaxa 3488, pp. 63-79 : 66-68

Empis chiragra Bezzi

( Figs. 12 – 21, 79)

Empis chiragra Bezzi, 1909: 353 ; Melander, 1928: 151 (checklist); Collin, 1933: 231 (citation); Smith, 1967: 21 (catalogue); Yang et al., 2007: 132 (catalogue).

Diagnosis. Dark brown to black, shiny; proboscis 2X head height; scutellum with pair of setae; legs yellow; wing slightly yellow, veins yellow, pterostigma inconspicuous; hind trochanter with ventral protuberance; apex of hind tibia clavate with 2 robust subapical setae in a chamber; base of hind tarsomere 1 with small, yellow, semilunar lamelliform apophysis; sternite 5 with median-apical projection.

Re-description. Lectotype male. Body length 3.3 mm; wing length 4.0 mm. Holoptic; dorsal ommatidia slightly larger. Frontal triangle black. Ocellus glassy, brown; anterior ocellar setae divergent, posterior ones small. Face bare, roughly same width as ocellar tubercle, twice as high as wide, roughly half as high as frontal triangle, black with distal extremity brown, shiny, slightly protuberant. Postcranium ( Fig. 12) black with uniserial postocular setae, 3 more robust on superior half; 2 median setae on occipital row. Gena with 4–5 slender setae and postgena with 1 seta. Antenna ( Fig. 13) with scape and pedicel yellow to brown; postpedicel black, coniform, roughly twice as long as scape and pedicel together, twice as long as stylus. Proboscis ( Fig. 12) 2X head height; labrum yellow, shiny; labium black. Palpus not visible.

Thorax ( Fig. 14) with exudate that obstructs colors and setae, but black (pruinescence not observed). Chaetotaxy: 3–4 uniserial antepronotals; 1 robust, 7–8 weak postpronotals; 1 robust, 1 weak proepimerals; 4–5 uniserial acrostichals; 4–5 biserial dorsocentrals, until transverse suture level; 1 pre- and 2 postsutural intra-alars; 1 pre- and postsutural supra-alars; 3 robust posterior and 2–3 weak anterior notopleurals; 1 postalar, 1 pair of crossed scutellar; roughly 8 laterotergitals, shorter than halter.

Legs yellow with few setae slightly longer than background setae. Foreleg ( Fig. 15): femur with 2 posterior subapical setae; tibia with equidistant posterodorsal row and distally with 1 antero- and 1 posteroventrals. Midleg ( Fig. 16): tibia with 3 equidistant posterodorsals and distally with 1 antero- and posteroventrals. Hindleg ( Fig. 17): coxa thicker, darker than anterior legs ( Fig. 18); trochanter with ventral protuberance ( Fig. 18); femur with complete anteroventral row, distal 2 setae largest ( Fig. 17); tibia clavate distally, with 2 robust subapical dorsal setae in chamber ( Fig. 17); ventral base of tarsomere 1 with small yellow lamelliform semilunar apophysis.

Wing ( Fig. 79) slightly yellow, pterostigma inconspicuous, veins yellow; costal vein with basal stout seta (not represented in figure). Vein R 1 bare dorsally, not dilated towards apex. Halter with black capitulum.

Abdomen black with light grey pruinescence, covered with distinct setae. Sternites lighter than tergites, except sternite 5 black and with median-apical protuberance ( Fig. 19). Sternites 6 and 7 with sclerotized areas. Tergite 8 narrow; sternite 8 large.

Terminalia ( Fig. 19). Epandrium subtriangular; cercus with many setae and apparently with very robust apical setae (broken); hypandrium membranous distally, joined to subtriangular protuberance by narrow sclerotized arch; ejaculatory apodeme flattened laterally ( Fig. 21); phallus rather transparent distally with two ducts ( Fig. 20).

Female. Unknown.

Geographical distribution. Peru.

Material examined. LECTOTYPE ♂ (here designated). “ PERU [Cuzco] Laristhal (= Paso de Lares ), 10.viii.1903, 2000 m ” (SMT).

Lectotype condition. Head and thorax with exudate. Right foreleg and left midleg glued to the paper triangle; right wing partially damaged, glued to the paper triangle; left wing in microslides. Abdomen in microvial with glycerin.

Remarks. This species was described based on two specimens from same locality. Only one specimen deposited in Dresden was examined.

Discussion. The male specimen of E. chiragra was identified as part of group II in Collin’s (1933) key through the same couplets as E. angustipennis presented above. Further in the key it runs to couplet (19) of E. macrura Bigot, 1889 through: (16) “thorax blackish without distinct stripes”; (16b) “face bare” and (19) “legs entirely tawny-yellow, hind femora of male simple, without setae behind at base”. They are not conspecific because E. chiragra differs by the absence of thoracic stripes (two stripes in E. macrura ), 1 pair of scutellar seta (4–6 in E. macrura ), trochanter with ventral protuberance ( Fig. 18) (no protuberance in E. macrura ), hind tibia clavate distally and 2 robust subapical setae in a chamber ( Fig. 17) (unmodified hind tibia in E. macrura ), base of hind tarsomere 1 with small yellow lamelliform semilunar apophysis (unmodified in E. macrura ). Terminalia are also different (compare Collin (1933, fig 52b) with Figure 19 presented here).