Strongylophthalmyia minutissima, Galinskaya & Shatalkin, 2018

Galinskaya, Tatiana V. & Shatalkin, Anatoly I., 2018, Seven new species of Strongylophthalmyia Heller, 1902 (Diptera: Strongylophthalmyiidae) from the Eastern Palaearctic and Oriental Regions with notes on peculiar rare species, Zootaxa 4402 (1), pp. 113-135 : 122

Strongylophthalmyia minutissima , n. sp.

( Fig. 6 )

Material examined. Holotype: ♂, Thailand, Phuket, env. Nai Yang beach, 6–10.XII 2009, leg. N. Vikhrev ( ZMMU).

Diagnosis. This new species is characterized by the following combination of characters: male antennal flagellomere unmodified, without dorsal process; fore femur without dorsal spicules; arista bare; thorax and abdomen entirely black; legs yellow, hind femur with preapical brownish ring; wing hyaline; mesonotum slightly matte, sparsely clothed with short pale setulae; frons black shining, yellow in anterior third up to fore ocellus; face yellow; palpus entirely yellow; small size: body length 1.8 mm.

Externally, this new species is similar to S. dichroa from Vietnam, S. indica from India (Meghalaya) and S. paula Shatalkin, 1993 from the Palaearctic in general body coloration. S. dichroa and S. indica are characterized by a bicolored palpus (new species with monochrome yellow palpus) and larger body sizes: 4.8 mm in S. dichroa and 3.5 mm in S. indica (the new species is 1.8 mm long). Furthermore, the frons is entirely black in S. dichroa (new species has the frons mostly black, yellow in anterior third). S. paula differs from the new species in the wide brown ring medially on the hind tibia, frons entirely black, and body length 2.1–3.0 mm (the new species has the hind tibia yellow, frons black with yellow anterior third, and body 1.8 mm long).

Description. Male. Head black, 1.1 times as long as high. Frons shining black, yellow in anterior third up to fore ocellus; widened towards vertex, its anterior width about 0.83 times as great as width at level of fore ocellus, its height (up to hind ocelli) about 0.67 times as great as its anterior width; frontal index equal to 0.6. Occiput black, slightly concave medially. Face yellow with row of short setulae along suture. Gena yellow with whitish pubescence. Antenna yellow, first flagellomere about 0.9 times as wide as its width; its marginal setulae pale and rather long, only 0.5 times as long as first flagellomere; arista dark brown, bare. Palpus relatively wide, yellow with black setulae apically. Mouthparts yellow. Frons between upper orbital and outer vertical setae without short setulae. Three reclinate fronto-orbital setae, one ocellar seta, one postocellar seta, one inner and one outer vertical seta, three setula-like short frontal setae.

Thorax black. Mesonotum slightly matte, densely clothed with short pale setulae. Pleuron shining. Scutellum matte. One thin presutural intra-alar seta, one dorsocentral seta, acrostichal setae not differentiated, two notopleural setae, one supraalar seta, one postalar seta, one anepisternal seta, one stout apical scutellar seta.

Legs yellow, hind femur with brownish preapical ring.

Wing unpigmented. Vein R2+3 intermediate in length: costal index = 1. Ratio between distance from R4+5 to M1+2 at level of dm-cu and length of costal vein between R4+5 and M1+2 equal to 1.9. Discal index = 2.7. Median index = 0.53. Calypter grayish with fan of long darkish setulae on margin. Halter with darkish stem and slightly brownish knob.

Abdomen black matte, posterior tergites slightly shining.

Lengths. Body, 1.8 mm; wing, 1.4 mm.

Female unknown.

Etymology. The specific epithet is the feminine form of the Latin “minutissimus” (smallest).

Figures

FIGURE 6. Strongylophthalmyia minutissima n. sp. Male holotype: a—habitus, lateral view; b—head, lateral view; c—head, anterior view; d—wing; e—head and thorax, dorsal view.