Empis liodes 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 : 71-73

Empis liodes Bezzi

( Figs. 41–49, 82)

Empis liodes Bezzi, 1909: 350 ; Melander, 1928: 160 (checklist); Collin, 1933: 231 (citation); Smith, 1967: 23 (catalogue); Yang et al., 2007: 136 (catalogue).

Diagnosis. Dark brown to black, subshiny; scutum with faint (but distinct in anterior view) black stripes between acrostichal and dorsocentral rows; 1 postsutural acrostichal; wing brown, broad; halter and legs yellow, posterior legs darker; mid and hind femora and tibiae flattened laterally, with peniform setae; female cercus short.

Re-description. Holotype female. Body length 4.3 mm; wing 4.8 mm. Dichoptic; frons and face black, conspicuously grey pruinescent and slightly wider than ocellar tubercle, both twice as high as wide. Frons with 4 small proclinate setae. Ocellus glassy, yellow; anterior ocellar seta divergent, with 3–4 tiny posterior setae. Face bare, protuberant distally ( Fig. 41). Postcranium ( Fig. 41) dark brown to black with grey pruinescence; with postocular setae uniserial, vertical setae more robust, 2 occipital setae directly posterior to vertical ones. Gena with longer, more numerous setae than postgena. Antenna ( Fig. 42) velvety matte-black, finely grey pruinescent; postpedicel coniform, 1.5X longer than scape and pedicel combined, 3X longer than stylus. Proboscis 2X head height ( Fig. 41); labrum brown on basal half, yellow on distal half; labium brown. Palpus hidden.

Thorax ( Fig. 43) dark brown to black, except yellowish on margins of postpronotal lobe, postalar callus, scutellum and laterotergite; pruinescence greyish-brown on scutum and scutellum, light grey on notopleuron, postpronotal lobe and mesopleuron. Scutum with faint black longitudinal stripes between acrostichal and dorsocentral rows ( Fig. 43), distinct in anterior view, slightly extending past transverse suture. Chaetotaxy: 5 distinct uniserial antepronotals; 1 robust, 3 weak postpronotals; 2 slender proepimerals; 1 postsutural acrostichal; 5 uniserial dorsocentrals; apparently no intra-alar; 1 presutural supra-alar; 1 shorter postsutural supra-alar; 3 robust, 2 tiny notopleurals; 1 postalar; 2 scutellars, apical pair longer, crossed; 12 laterotergitals.

Legs yellow, hind pair darker, all grey pruinescent when seen in certain angles, more conspicuous on coxae. Foreleg ( Fig. 44): tibia with row of short antero- and posterodorsal setae, slightly more robust than background setae; tarsomeres 1 and 2 with short, robust, setae medially and distally. Midleg ( Fig. 45): femur and tibia flattened laterally; femur with dorsal and ventral peniform setae throughout length, dorsals shorter; tibia with peniform setae throughout dorsally and shorter ventrally at basal half; tibia with row of 4 antero- and posterodorsal setae, 1 longer anteroventral seta at middle, 2 shorter anteriors subapically. Hindleg ( Fig. 46): coxa shorter, thicker than fore and mid coxae; femur and tibia flattened laterally, both with long dorsal and ventral peniform setae along entire length, except on ventral distal fourth of tibia; femur with posteroventral row of small peniform setae, tibia with posterodorsal row of small peniform setae.

Wing ( Fig. 82) wide, with rounded apex, brown, with inconspicuous pterostigma; base of costal vein with robust seta (not represented in figure). Vein R 1 bare dorsally, slightly dilated towards apex. Halter yellow.

Abdomen brown, subshiny, covered with small black setae, longer on posterior margin of tergites; grey pruinescent laterally on tergites. Sternites same color as tergites.

Terminalia with tergite 8 and sternite 8 of same length ( Fig. 47); sternite 8 with apex projected ventrally; sternite 10 ( Fig. 49) wider than tergite 10 ( Fig. 48), with 2 paramedian sclerotized bands and short robust setae at base and thin setae at apex; genital fork triangular ( Fig. 47); genital fork subtriangular ( Fig. 47); cercus shorter than sternite 10 ( Figs. 47, 49) with robust marginal setae ( Figs. 48, 49).

Male. Unknown.

Geographical distribution. Peru.

Material examined. HOLOTYPE ♀. “ PERU, [Pasco], Pichis, Puerto Bermudes , 11.xii.1903 ” (300 m) (SMT).

Holotype condition. Left postpedicel lost; right wing on microslide; terminalia in microvial with glycerin.

Discussion. The female specimen of E. liodes is identified as part of group VI in Collin’s (1933) key, but it does not fit the couplet’s characters very well. Through the key it does not agree with any option of couplet (1) and in couplet (52) characters as “no acrostichals (rarely only 2–3 minute pairs), only 3–4 pairs of isolated fine dorsocentrals, axillary lobe of wing not much developed and long-legged flies” it does not agree by 1 pair of acrostichals, but not minute, 6 pairs of dorsocentrals and rather short-legged in E. liodes . Empis liodes agrees only by axillary lobe undeveloped. Further in the key it runs to couplet (64) of E. omissa Collin, 1933 through (53) “no acrostichals (occasionally 1–2 in E. omissa , ♂)”; (64) “very small species with about two pairs of tiny acrostichal setae”. However E. liodes has only 1 pair of acrostichal setae, but not minute and does not agree due to its greater size 4,2 mm in E. liodes against 2,5 mm in E. omissa . Besides the key characters, the female specimen of E. liodes bears peniform setae on mid and hindlegs, which are absent in E. omissa .