Lactistomyia insolita Melander

Ale-Rocha, Rosaly, 2008, Revision of the Neotropical genus Lactistomyia Melander (Diptera, Hybotidae, Hybotinae), Zootaxa 1692, pp. 1-25 : 5-7

Lactistomyia insolita Melander

( Figs. 1–6 , 55 )

Lactistomyia insolita Melander, 1902:251 ; 1928: 35 (pl. 5. fig. 45); Smith, 1962:216 (citation, original description); 1967:14 (catalogue).

Diagnosis. Wing brown, stigma brown; hind femur strongly swollen, with 12 curved ventral spines, ninth spine located more ventrally, tubercles 6–9 longer or subequal to spines, posteroventral row with 7 spines increasing in length towards apex; hind tibia remarkably curved with anterior surface flattened with soft longitudinal furrow, 1 small anteroventral tubercle on basal third; hypandrial lobe expanded distally, as long as hypandrium; epandrial lamellae with preapical short and stout bristles.

Holotype male. Body: 5.5 mm; wing: 4.5 mm (original measures).

Redescription (based on the original description complemented with the exam of recent specimens). Antenna brown, pedicel with short setae; postpedicel twice longer than wide, as long as scape and pedicel combined; arista 3 times length of antenna. Face narrow, black with brown pruinescence. Palpus brown; proboscis yellow. Ocellar setae weak, short, parallel and almost erect. Postcranium dark-brown with mixed graybrown pruinescence; postocular setae brown, short, weak and scattered; occipital setae elongate and scattered, present on lower half.

Thorax with rust colored pruinescence; scutum black, pronotum and scutellum brown, postpronotal lobe brown with yellow margins, postalar callus yellow; pleurae brown except posterior margin of the katepisternum, anepimeron, laterotergite and lower margin of the meron pale brown. Bristles pale brown to gold, weak, short and abundant; pronotum with marginal bristles biserial in the middle and more numerous laterally; 1 robust npl; 1 slightly more robust pal; scutellum with 1 preapical pair long, convergent, 4–5 thin lateral bristles about ½ to one-third length of preapical pair and 2–3 thin and short apical bristles ( Fig. 1 ).

Fore and mid legs yellow; hind leg with yellow coxa, pale brown trochanter, femur brown with base and posterior surface pale brown and yellow apex, tibia pale brown with black dorsal surface and pale brown to yellow tarsus. Bristles yellow, spines of hind femur brown. Hind femur not surpassing the abdomen in length, strongly swollen, sparsely bristled, nude ventrally. Hind tibia remarkably curved with dorsal and anteroventral surfaces sharpened, anterior surface nude and flattened with soft longitudinal furrow, posterior surface convex, 1 small anteroventral tubercle on basal third, twice length of tarsus ( Fig. 6 ). Fore and mid tarsi long with tarsomere 1 as long as following tarsomeres combined; hind tarsus half length of fore and mid tarsus, tarsomere 1 about 1.3 times length of following tarsomeres combined, tarsomeres 2–4 very short. Outstanding bristles: fore tibia with 1 short anteroventral and 1 short posteroventral preapical bristles; mid tibia with elongate bristles on posterior surface, 3–4 short anterodorsal bristles, 1 long ventral apical bristle reaching the half of tarsomere 1 and some shorter apical bristles; mid tarsus with 1 anterodorsal preapical, 1 anterodorsal and 1 posteroventral bristles in the middle; hind trochanter with 1 short and strong ventral dark brown spine; hind femur with 12 ventral curved spines with ninth spine located more ventrally and basal tubercles 6–9 longer or subequal to spines, posteroventral row with 7 spines increasing in length towards apex, thinner than the ventral ones; hind tarsus with small anteroventral yellow tubercles on tarsomere 1.

Wing ( Fig. 55 ): brown tinged, slightly more dark in the costal margin; stigma brown; costal cell as wide as R1; R4+5 and M1 convergent; anal lobe wide.

Abdomen pale brown to brown, with dense rust colored pruinescence on all segments. Bristles yellow, very thin, short dorsally and long on lateral margin, distinctly longer on Tg1–Tg3; sternites with short, thin, scattered bristles, longer on distal margin of sclerites. Terminalia: hypandrium strait, very long, surpassing the length of the epandrium; hypandrial lobe clavate and round distally, as long as the basal portion of hypandrium ( Fig. 2 ); epandrial lamellae with preapical bristles shorter than half of length of each respective lamella ( Fig. 3 ); surstyli large, right surstylus wide and plane, left surstylus with three faces ( Figs. 4, 5 ).

Female: unknown.

Type material. Holotype male ( USNM): "Chapada, Brazil ".

Additional material. BRASIL, Mt [Mato Grosso], C. [Chapada] Guimarães, Malaise, 22–30.xi.1983, Bindá, 1 male ( INPA); Maranhão, Caxias, Faz. [Fazenda] Bode, 043554S-430737W, 07–12.iii.1997, J. A. Rafael & F.L. Oliveira, varredura, 3 males ( INPA).

Condition: the holotype of L. insolita is damaged, only some parts of the holotype body are still present. The left hind leg of the specimen remains gummed on a triangle of paper. Because the hind leg bearing some of the most important diagnostic characters of the species in Lactistomyia , and the leg of L. insolita is very distinctive, it was possible to identify other specimens of L. insolita for comparison with this part of the body of the type specimen plus the original description.

Remark: the examined specimens presented body on average with 6.5 mm, and wing with 5.0 mm length.

Distribution: Brazil (Maranhão, Mato Grosso).

Figures

FIGURES 1 – 6. Lactistomyia insolita. Male. 1, scutellum; 2, 3, hypopygium, ventral and dorsal view; 4, 5, right and left surstyli; 6, hind leg. Figs 2 – 5 in the same scale. Scale bar = 0.5 mm. Abbreviations: cerc, cercus; ej apod, ejaculatory apodeme; epand, epandrium; hypd, hypandrium; ph, phallus; sur, surstylus; ph, phallus; pgt, postgonite.

FIGURES 54 – 63. Wings of Lactistomyia. 54, L. hyalina; 55, L. insolita; 56, L. lepida sp. n.; 57; L. mammifera; 58, L. minuta sp. n.; 59, L. nigripes; 60, L. paranaensis sp. n.; 61, L. pulchra sp. n.; 62, L. serrata; 63, L. tuberculata sp. n.