Drapetis dissentis, Solórzano Kraemer & Sinclair & Cumming, 2005

Solórzano Kraemer, Mónica M., Sinclair, Bradley J. & Cumming, Jeffrey M., 2005, Five new species of Tachydromiinae (Diptera: Empididae s. l.) from New World Tertiary ambers, Zootaxa 1010, pp. 37-52 : 45-47

Drapetis dissentis sp. nov.

DIAGNOSIS. This species of Drapetis is distinguished by its wing venation with R 4+5 slightly sinuous and strongly divergent from M 1+2, as well as the apparent absence of ommatrichia and characteristic squamiform setae on male abdominal tergite 4 and 5 ( Fig. 3).

DESCRIPTION. Male ( Fig. 3A). Length 1.64 mm. Head. Ground colour dark. Eyes apparently lacking ommatrichia (pubescence); narrowly separated below antennae; facets not noticeably enlarged below antennae. Frons with sides divergent; narrow just above antennae and slightly wider on vertex than width of ocellar triangle. Two pairs of ocellar bristles; anterior pair convergent, inserted between median and posterior ocelli and broadly separated; posterior pair inserted between posterior ocelli. Two pairs of convergent vertical bristles. Antennae arising slightly above middle of head; scape small, shorter than half length of pedicel; pedicel globose, two­thirds as long as postpedicel, lacking long ventral preapical bristle; postpedicel short­conical, with terminal arista­like style shorter than scutum; antennal segments concolorous (dark brown). Palpus ovate with several long, apical setulae.

Thorax. ( Fig. 3B) Ground colour dark. Scutum entirely clothed in dense microtrichia, scutellum lacking microtrichia. Postpronotal lobe and bristles absent; 2 pairs of prescutellar acr; 1–2 npl; 1 pair of prescutellar dc; spal not clearly differentiated; 1 pal; 1 subapical pair of sctl, less than one­half length of apical sctl; 1 apical pair of sctl long and conver­ gent. Scutum appears entirely shiny, lacking tomentum; scutellum perhaps with tomentum on at least anterior half.

Wing. ( Fig. 3C) Length 1.3 mm. Broad with blunt­tip; hyaline; microtrichia evenly distributed; costal setulae well developed; Rs about one­half length of cell bm; R 2+3 strongly arched, extending to beyond mid­length of wing; R slightly sinuous, divergent from M 1+2; cell br much shorter than cell bm; crossvein bm­cu nearly transverse. Knob of halter dark.

4+5

Legs. Fore and mid femora moderately thickened. Mid femur with 1 outstanding preapical anterior bristle; mid tibia somewhat arched; first tarsomere with biserial ventral row of short bristles, slightly shorter than width of segment. Hind femur slightly bent near base, with row of short anteroventral bristles longer near apex. Hind tibia slightly arched with posteroventral row of short bristles.

Abdomen. Segments uniformly telescopic, without distinctive flattened hook­like squamiform setae on tergite 4 and 5. Terminalia ( Fig. 3D): Right surstylus as long as terminalia, with stout inner marginal bristles. Right cercus slender, slightly tapered. Left cercus broad, digitiform, only slightly tapered to rounded apex. Hypandrium broad and truncate apically.

TYPE. Holotype male from Mexico: B­8414­30. Housed in UCB (type number 50026). The holotype is in a subrectangular piece of dark amber measuring about 10 x 6 mm.

REMARKS. The inclusion was found together with a specimen of Cecidomyiidae . Extant species of Drapetis are found in a wide variety of habitats on vegetation and tree trunks, in rodent burrows, and in ant nests ( Rogers 1983).

ETYMOLOGY. From the Latin, dis (without) and sentis (thorn), in reference to the lack of squamiform setae on male abdominal tergite 4 and 5.