Strongylophthalmyia malayensis Evenhuis, 2016

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 : 133-135

Strongylophthalmyia malayensis Evenhuis

( Fig. 12 )

Strongylophthalmyia malayensis Evenhuis, 2016: 226 (male)

Material examined. ♀, Malaysia, Sabah st 1430 m, Mt. Kinabalu (5.977°N, 116.579 °E), 13–17.II.2014, N.Vikhrev leg. ( ZMUM).

Systematic remarks. This female specimen can be identified as Strongylophthalmyia immaculata Hennig in both in Frey’s (1956) and Steyskal’s (1971) keys, but S. immaculata differs from S. malayensis in smaller size: body, 2.2 mm; wing, 2.0 mm in description of the male ( Evenhuis, 2016, p. 222); wing, 2.5 mm in description of Hennig (1940, p. 310, Fig. 16). S. immaculata belongs to S. punctata group sensu Evenhuis (2016) with males possessing a dorsal antennal process. This group includes two subgroups: punctata subgroup characterized by the presence of thorn-like spicules dorsally on the fore femur in males and coarctata subgroup without thorn-like spicules. We have checked the descriptions of all known species of both subgroups. The species of the second subgroup are characterized by the black coloration of the mesonotum. Therefore, our specimen of the female is one of the species of the first subgroup and, along the whole set of primary morphological characters, could be associated with S. immaculata or with S. malayensis or with the unknown species. It is impossible to describe new species based on females, if there are no good diagnostic characters. Therefore, only the associations with S. immaculata or with S. malayensis are considered here.

Evenhuis (2016) presented a large compilation of wing photos of the punctata subgroup species, summarizes in tables.

These tables show that in the wing venation S. immaculata ( Evenhuis 2016: Fig. 54) and S. malayensis ( Evenhuis 2016: Fig. 54) are similar to each other and to the specimen of a female described below ( Fig. 12a, e ) and differ from other species of Strongylophthalmyia in the following character: veins R4+5 and M1+2 converging distally. To assess the level of convergence of these veins, it is needed to determine next indicators. First indicator is the ratio of distance between veins R4+5 and M1+2 at the level of dm-cu and the length of dm-cu. Second indicator is the ratio of distance between veins R4+5 and M1+2 at the level of dm-cu and distance of the costal vein between R4+5 and M1+2. First indicator is equal: in S. immaculata 1.4; in S. malayensis (male) 2.1; in S. malayensis (female) 2.1. Second indicator is equal: in S. immaculata 2.0; in S. malayensis (male) 2.3; in S. malayensis (female) 2.6 (2.7). Discal index is equal: in S. immaculata 2.1 in Evenhuis (2016) and 2.2 in Hennig (1940); in S. malayensis (male) 3.5; in S. malayensis (female) 3.5. As we can see, the wing indices show a closer relationship of female specimen to the male of S. malayensis , rather than the male of S. immaculata .

Description. Female. Head yellow, slightly longer (1.1 times) than high; frons with matte black triangular spot including ocellar triangle and restricting by outer vertical and postocellar setae behind; frons with two narrow short blackish stripes along eye margin separated one from another by yellow area; frons slightly widened towards vertex, its anterior width about 0.8 times as long as its width at level of first ocellus, frontal length about 0.9 times as long as its anterior width. Frontal index = 1.1. Occiput poorly convex (seen from above). Face yellow with row of yellow setulae along suture; clypeus yellow, shining. Gena with silver gray pubescence of short setulae. Antenna yellow, flagellomere yellowish gray, widely yellow basally, with short yellow dorsal setulae; its length about 0.9 times as long as wide. Arista dark brown, bare. Mouthparts and palpus yellow. Frons between upper orbital and outer vertical setae without short setulae. Three reclinate to lateroclinate orbital setae, one ocellar, one postocellar, one inner and one outer vertical setae, three large, reclinate to lateroclinate and two short, setula-like fronto-orbital setae.

Thorax yellow; mediotergite brownish-yellow. Mesonotum slightly shining, sparsely covered with short pale setulae; pleuron shining; scutellum bare, matte. One dorsocentral seta (yellowish), two notopleural setae, one supraalar seta, one postalar seta, one anepisternal seta, one stout apical scutellar seta.

Legs yellow, last tarsal segment darkened; spurs on mid and hind tibiae yellow.

Wing transparent. Costal index = 0.7. Apical section of vein M1+2 curved in direction of vein R4+5; First indicator = 2.1 and; second indicator = 3.5. Discal index = 3.5. Medial index = 0.6. Cell bm about 0.4 times as long as cell dm. Calypter yellowish with fan of very long yellowish setulae on margin. Halter with yellow stem and whitish knob. Abdomen black, shining, segment 1 and ovipositor yellowish.

Lengths. Body, 3.8 mm; wing, 3.5 mm.

Figures

FIGURE 12. Strongylophthalmyia malayensis Evenhuis, 2016. Female: a—habitus, lateral view; b—head and thorax, dorsal view; c—head, anterior view; d—head, lateral view; e —wing.