Empis induta 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 : 68-69

Empis induta Bezzi

( Figs. 22–31, 80)

Empis induta Bezzi, 1909: 348 ; Melander, 1928: 159 (checklist); Collin, 1933: 231 (citation); Smith, 1967: 22 (catalogue); Yang et al., 2007: 135 (catalogue).

Diagnosis. Yellow, subshiny; setae black; proboscis 4X head height; 1–2 acrostichal setae; presutural intra-alar setae present; wing slightly yellow, pterostigma inconspicuous, yellow; halter yellow; mid and hind femora, mid and hind tibiae with peniform setae; female cercus short.

Re-description. Holotype female. Body length 4.2 mm; wing length 4.6 mm. Dichoptic; head black. Frons yellow, finely grey pruinescent, longitudinally sulcate (probably due to drying), as wide as ocellar tubercle, but slightly narrow medially, height slightly more than twice width, with 4 pairs of small proclinate setae ( Fig. 23). Ocellar tubercle yellow, grey pruinescent, with divergent anterior setae, 3 small, aligned posteriors. Ocellus glassy, reddish. Face bare, as wide as frons, subquadrate, short, half frons height, with dorsal half grey pruinescent, ventral half protuberant, yellow, subshiny, sparsely grey pruinescent. Postcranium dark brown to black, grey pruinescent, except directly behind ocellar tubercle and on postgena light yellow; uniserial postocular row of setae complete, vertical ones more robust, 2 posterodorsal occipital setae ( Fig. 22). Gena and postgena with a few short setae. Antenna ( Fig. 24) yellow, except apex of postpedicel and stylus brown; postpedicel coniform with dilated base, 2X longer than scape and pedicel together, 3X longer than stylus. Proboscis yellow, darker distally, roughly 4X longer than head height ( Fig. 22). Palpus hidden, yellow, with small black distal setae.

Thorax yellow with black setae; grey pruinescence more conspicuous on scutum, scutellum, subscutellum and anatergite. Chaetotaxy ( Fig. 25): 6 antepronotals arranged in fan; 1 robust, 3 weak postpronotals; 2 proepimerals, 1 more robust; 2 uniserial acrostichals; roughly 8 misaligned dorsocentrals, apparently biserial at level of transverse suture, posterior setae farther apart; 1 presutural intra-alar; 1 pre- and postsutural supra-alars; 3 strong, 1 weak anterior notopleurals; 1 robust and 1 weak anterior postalars; 2 scutellars (apical pair broken); 12 laterotergitals, roughly 0.75 halter length.

Legs yellow with black setae. Foreleg ( Fig. 26, setae not represented): with short, distinct setae. Midleg ( Fig. 27): femur with peniform posteroventral setae on distal half; tibia with dorsal peniform setae throughout, slender, longer setae, being 2 anterodorsals in basal half, 4 equidistant posterodorsals throughout, 5 anteroventrals on distal two-thirds, apical anteroventral setae shorter; tarsus with short, more robust setae. Hindleg ( Fig. 28) coxa shorter and thicker than fore and mid coxae; femur with peniform posteroventral setae throughout, 2–3 slender anterodorsal slightly more robust than others; tibia with peniform dorsal setae throughout, 1 posteroventral on basal third, slender 4 anterodorsals, 4 equidistant posterodorsals and 4 shorter anteroventrals on distal half; tarsomere 1 with 1 robust dorsal, 1 robust anterodorsal, 1 robust posterodorsal seta.

Wing ( Fig. 80) slightly yellow, more strongly so on costal margin, pterostigma tenuous, yellow, veins yellow; costal vein with robust basal seta (not represented in figure). Vein R 1 bare dorsally, not dilated towards apex. Halter yellow.

Abdomen yellow, shinier than thorax, with black setae, distal margin of tergites with longer uniserial setae.

Sternites with same color as tergites, with fainter setae.

Terminalia with sternite 8 modified, apex projected ventrally ( Fig. 29); sternite 10 ( Figs. 29, 31) wider than tergite 10 ( Fig. 30) with short, robust setae at base and slender setae at apex; genital fork slightly bilobed at apex ( Fig. 29); cercus shorter than sternite 10 ( Fig. 29) with robust marginal setae ( Figs. 30, 31).

Male. Unknown.

Geographical distribution. Peru.

Material examined. HOLOTYPE ♀. “ PERU, [Pasco], Pichis, Puerto Bermudes , 14.xii.1903 (300 m)” (SMT).

Holotype condition. Right postpedicel and left foreleg lost; right wing on microslide; abdomen in small tube with glycerin.

Discussion. The female specimen of Empis induta is identified as part of group VI in Collin’s (1933) key, but it does not agree with the couplet characters very well. In the key it does not fit couplet (1) and in couplet (52) “no acrostichals (rarely only 2–3 minute pairs) and only 3–4 pairs of isolated fine dorsocentrals; axillary lobe (= alula) of wing not much developed; small, slender, long-legged flies” it agrees by alula undeveloped and 2 pairs of acrostichals but not minute. It does not fit couplet (52) by 8 pairs of dorsocentrals and by rather short legged flies. Further in the key it runs to couplet (64) of E. omissa Collin, 1933 through “two pairs of tiny acrostichal setae; dorsocentrals shorter than usual”, but acrostichals are not minute and the length of the dorsocentrals is as usual in E. induta . Besides key characters, female specimens of E. induta possess peniform setae on the mid and hindlegs, whereas they are absent in O. omissa , and size 4.2 mm against 2.5 mm in E. omissa .