Stilobezzia (Eukraiohelea) quasielegantula Cazorla and Felippe-Bauer 2017, n. sp.

Stilobezzia (Eukraiohelea) quasielegantula Cazorla & Felippe-Bauer n. sp.

(Figs. 29 ¯42)

Diagnosis. The only Neotropical species of Stilobezzia (Eukraiohelea) of medium size (wing length 1.17–1.37 mm) with general coloration pale yellowish and brown transverse bands on abdominal tergites with two small, round clear spots on their mid portions. Male gonocoxite with a conspicuous sclerotized membrane arising from dorsal inner margin; gonostylus swollen subapically with curved, sclerotized pointed apical projection; and apices of parameres greatly elongate and recurved 100˚. Female with tarsomere 5 of fore and mid legs with 2 pairs of batonnets and tarsomere 5 of hind leg with only 1 pair.

Male. Head. (Fig. 29) dark brown. Antenna with flagellomeres 1–10 pale brown basally, brown distally, flagellomeres 11–13 dark brown with pale brown basal ring; flagellomere 13 more than twice as long as 12; plume brown, well developed; antennal ratio 1.07–1.23 (1.15, n = 7). Palpus (Fig. 30) dark brown; third segment elongate with small, shallow subapical sensory pit; palpal ratio 3.00–3.70 (3.47, n = 10).

Thorax. Scutum pale brown (as Fig. 42, female), prescutellar depression light yellowish; scutellum light yellowish with 4 stout, 1–2 thinner setae; postscutellum brown. Legs yellowish; narrow apex of hind femur, basal 1/3, narrow apex of hind tibia dark brown; fore femur with 2 – 3 short, stout ventral spines; tarsomere 1 of mid leg with long, slender, straight basal spine; tarsomere 1 of hind leg with stout, slightly curved basal spine; hind tibial comb with 5 – 6 spines; fore leg tarsal ratio 2.50–2.67 (2.60, n = 9); mid leg tarsal ratio 2.75–3.04 (2.92, n = 7); hind leg tarsal ratio 2.62–2.85 (2.72, n= 10); tarsomere 5 of all legs with 1 pair of batonnets (Fig. 31), claws large, with long basal tooth, claws of hind leg longest. Wing (Fig. 32) membrane hyaline; r-m crossvein oblique; cubital fork distal to level of base of r-m crossvein; wing length 1.17–1.25 (1.20, n = 10) mm, width 0.40–0.45 (0.40, n = 10) mm; costal ratio 0.70–0.75 (0.72, n = 10). Halter dark brown.

Abdomen. Tergites with broad transverse dark brown bands with two small, round pale spots on their midlines; sternites dark yellowish. Genitalia (Figs. 33 ¯35): tergite 9 extending slightly beyond apices of gonocoxites, distal margin rounded with very shallow mesal notch; apicolateral processes lobate, moderately elongate, slender, overlapping along their inner margins with the broad, rectangular cerci (Fig. 35); sternite 9 2.80 X broader than long, posteromedian portion not clearly distinguishable. Gonocoxite 1.8 X longer than greatest breadth, stout proximally, nearly triangular, tapering distally with a sclerotized membrane extending from dorsal inner margin to apices of parameres, lateral margins straight, outer margins are slightly curved distally they don’t converge; gonostylus light brown, stout, 0.70 X the length of gonocoxite, swollen subapically, apex with a sclerotized, curved, pointed projection. Parameres parallel, gonocoxal apodemes stout, bilobed; proximal ¼ portions slender, sclerotized, distal ¾ portions broader, apices elongate, greatly divergent, recurved 100˚, tapering to pointed tips. Aedeagus (Fig. 34) represented by 2 arched, slender sclerites, each with basal portion curved, sclerotized, distal portion rounded, sclerotized.

Female (Fig. 42). Similar to male, with the following notable sexual differences: Head (Fig. 36). Antenna with proximal ½ of flagellomeres 1–8 pale brown, distal 1/2 dark brown, flagellomeres 9–13 dark brown with pale basal ring; antennal ratio 1.42–1.62 (1.53, n = 8). Palpal ratio 3.10–4.00 (3.60, n = 8). Mandible with 7 – 8 teeth.

Thorax. Legs (Fig. 37): tarsomere 5 of fore leg, mid leg with 2 pairs of batonnets, hind leg with 1 pair of batonnets (Fig. 38); fore leg tarsal ratio 2.50–3.08 (2.65, n = 9); midleg tarsal ratio 2.77–3.04 (2.88, n = 9); hind leg tarsal ratio 2.50–3.00 (2.74, n= 9); claws of all legs almost as long as tarsomere 5, fore and mid claws slenderer than hind claw, all with moderately long basal tooth that is shortest on hind claw. Wing (Fig. 39) length 1.30–1.37 (1.32, n = 9) mm, width 0.47–0.55 (0.52, n = 9) mm; costal ratio 0.73–0.78 (0.76, n = 9).

Abdomen (Fig. 40): Proximal 2/3 or more tergites brown, distal portions lighter; broad lateral margins of tergites 8 dark brown. Genitalia (Fig. 41): sternite 8 light brown, with narrow U-shaped posteromedian excavation; sternite 9 halves heavily sclerotized, of similar shapes to those of S. proxima n. sp.; sternite 10 pale brown with 3 – 4 pairs of setae; cercus short with rounded apex. Two unequal-size, ovoid spermathecae with very short wide necks, measuring 50–65 (57, n=8) µ by 40–45 (42, n=8) µ and 48–58 (50, n=8) by 38–40 (40, n=8) µ; plus a small, round rudimentary third spermatheca measuring 10–12 (10.7, n =8) µ.

Distribution. Brazil (Rio de Janeiro).

Types. Holotype male, labeled “ Stilobezzia (Eukraiohelea) quasielegantula Cazorla and Felippe-Bauer, BRAZIL, Rio de Janeiro, Casimiro de Abreu, Union Biological Reserve (22°25’35” S 42°2’4” W), 07.XI – 13.XII.2013, "Biota Diptera Fluminense " team col, Malaise trap”, (CCER). Allotype female, 30 other paratypes: 9 males, 8 females with same data as holotype (7 males, 6 females, CCER; 2 males, 2 females, MLPA); 1 male, 1 female with same data except 25.VIII–26.XI.2013 (CCER).

Etymology. The species name quasielegantula refers to the great resemblance of this new species with its congener S. (E.) elegantula.

Discussion. Stilobezzia (E.) quasielegantula n sp. is very similar to S. (E.) elegantula and the new species S. (E.) proxima. Characters for distinguishing these two species from this new species are in key and in the discussion section of the latter species.