Dolichogenidea biconcava Liu & Chen, 2018

Liu, Zhen, He, Jun-Hua & Chen, Xue-Xin, 2018, The laevigata - group of the genus Dolichogenidea Mason, 1981 from China, with descriptions of 26 new species, Zootaxa 4436 (1), pp. 1-74 : 12-16

Dolichogenidea biconcava Liu & Chen , sp. n.

Figures 5 , 35

Description. Female. Body length 2.7 mm, fore wing length 3.2 mm.

Head. Less transverse in dorsal view, 1.8× as wide as long and a little narrower than mesoscutum (23.5:25.0). Temple shiny and indistinctly punctate, rounded. Face relatively shiny, finely shallow punctate, sparsely pubescent, inner margin of eyes parallel, subquadrate, 0.8× as high as wide. Ocelli relatively small, distance between fore and a hind ocellus smaller than diameter of an ocellus, posterior imaginary tangent to fore ocellus virtually touching hind two ocelli, POL:OD:OOL=4.5:2.2:3.8. Antenna nearly as long as body, penultimate antennomere 1.5× longer than wide.

Mesosoma. Length:breadth:height=45.0:25.0:28.0. Disc of mesonotum relatively shiny, finely punctate, interspaces smaller than diameter of punctures. Scutellar sulcus nearly straight, very narrow, shallow with sparse carinae in between. Scutellum shiny, with shallow sparse punctures. Propodeum shiny, with setose punctures anterior-laterally, areola U-shaped, middle part depressed and polished, posteral-lateral field polished. Mesopleuron highly polished, with shallow setose punctures anteriorly.

Legs. Spines on outer side of hind tibia thick, numerous and close-set. Inner spur of hind tibia1/3 length of hind basitarsus, outer spur slightly shorter (1/4). Basitarsus of hind leg weakly shorter than tarsomeres 2–4 combined (15.0:17.0).

Wings. Pterostigma 2.8× as long as its widest part. Vein 1-R1 (metacarp) 1.1× longer than pterostigma, 6× as long as its distance from the apex of the marginal cell. Vein r arising from apex of pterostigma, shorter than width of pterostigma, vein r slightly longer than vein 2-SR, distinctly angled at their meeting, vein 2-M half length of vein 2-SR. 1 st discal cell at least 1.3× wider than high. 1 st submarginal cell of hind wing 2× wider than high. Vein cu-a curved.

Metasoma. Longer than thorax (57.5:45.0). T1 subparallel, weakly constricted posteriorly, 1.4× longer than wide posteriorly, concave at basal third, turned-over part shallowly punctate to weakly wrinkled, middle part concave and polished, hind tubercle triangular and polished. T2 curved into T3, weakly wrinkled laterally, 4× wider than long in the middle. T3 twice longer than T2. Tergites after T2 shiny, polished, pubescent. Hypopygium not longer than apex of abdomen. Ovipositor sheath 1.3× longer than hind tibia, thin and parallel-sided.

Colour. Body black. Tegula black. Spurs pale yellow. Palpi yellow. Antenna and ovipositor sheath evenly brown. Labrum and mandible bright reddish brown. Fore and middle Legs mostly yellow except fore and mid coxae and anterior 2/3 of mid femur brown, hind leg mostly brown except anterior half of hind tibia and anterior quarter of hind basitarsus yellow. Wing membrane hyaline, vein 1-R1, C+SC+R, r, 2-SR, 2-M and pterostigma brown, other veins pale yellow, pterostigma with pale basal spot.

Viaration. Body length 3.5–5.0mm.

Male. Unknown.

Material examined. Holotype: ♀, Datianding, Dawuling , Guangdong, 2001. X.3, Xu Zaifu, No. 20020535 . Paratypes: 6♀♀, Datianding, Dawuling, Guangdong, 2001. X.3, Xu Zaifu , Nos. 20020558, 20020573, 20020564, 20020628, 20020636, 20020552 ; 3♀♀, Datianding, Dawuling, Guangdong, 2001. X.5, Xu Zaifu , Nos. 20021077, 20021105, 20020950.

Distribution. China (Guangdong).

Etymology. The specific name “ biconcava ” derived from the Latin prefix “bi-” and noun “concava”, referring to propodeum and T1 both concave medially.

Remarks. This species is extremely similar to D. infimus (Haliday) , but differs from the latter by the following: punctuation on mesoscutum more deep and distinct (the latter obsolescent); ovipositor sheath 1.3× longer than hind tibia (the latter as long as); and penultimate antennomere 1.5× longer than wide.

Figures

FIGURE 5. Dolichogenidea biconcava Liu & Chen, sp. n. a mesonotum and scutellum; b hind wing; c propodeum and metasoma, dorsal view; d head, dorsal view; e head, frontal view; f habitus, lateral view; g fore wing. Scale line = 0.5 mm.

FIGURE 35. Distribution map of laevigata-group of Dolichogenidea species in China.*: Dolichogenidea aberrantenna Liu & Chen, sp. n.; ■: Dolichogenidea aegeriphagous Liu & Chen, sp. n.; Δ: Dolichogenidea ancylotergita Liu & Chen, sp. n.; •: Dolichogenidea anteruga Liu & Chen, sp. n.; ♥: Dolichogenidea biconcava Liu & Chen, sp. n.;•: Dolichogenidea brevifacialis Liu & Chen, sp. n.; Ŧ: Dolichogenidea breviventris (Ratzeburg, 1848).