Bassus levisulcus Tang & Chen, 2017

Tang, Pu, Van Achterberg, Cornelis & Chen, Xue-Xin, 2017, The genus Bassus Fabricius, 1804 (Hymenoptera: Braconidae: Agathidinae) in China, with description of three new species, Journal of Natural History 51 (45 - 46), pp. 2745-2758 : 2754-2755

Bassus levisulcus Tang & Chen , sp. nov.

( Figure 4 )

Description

Holotype, ♀, length of body 8.3 mm, of fore wing 7.6 mm, of ovipositor sheath 9.0 mm.

Head. Antenna with 29 segments, length of third segment 1.15 times fourth segment; third, fourth and penultimate segments 3.75, 4.3 and 1.5 times their width, respectively; length of apical segment 1.3 times as long as penultimate segment; length of maxillary palp 0.6 times height of head; malar space 2.1 times as long as basal width of mandible; temple short, in dorsal view length of eye twice temple; ocelli in low triangle, POL:OD: OOL = 6:7:18; face with distinct fine punctures; frons shiny and smooth; vertex and temple shiny with sparse minute punctures.

Mesosoma. Length of mesosoma 1.5 times its height; subpronope shallow; pronotum largely smooth laterally, with sparse fine punctures dorsally; area near lateral carina of mesoscutum sparsely crenulate; lateral and middle lobes of mesoscutum sparsely and finely punctate, flat and smooth posteriorly; notauli complete, narrowly crenulate; scutellar sulcus 0.7 times as long as dorsal face of scutellum and with three carinae; scutellum slightly convex and distinctly narrowed, with lateral carina, shiny with sparse fine punctures, its subposterior crest curved; precoxal sulcus shallow, narrow, almost smooth; mesopleuron below precoxal sulcus nearly smooth; mesopleuron above precoxal sulcus largely smooth; metapleuron with distinct sparse punctures, areolaterugose ventrally; propodeum closely reticulate-rugose; propodeal spiracle small, 1.25 times as long as wide.

Wings. Fore wing: second submarginal cell triangular; vein SR1 straight; r:3-SR+SR1 = 4:47; vein cu-a distinctly postfurcal. Hind wing: vein M+CU 0.6 times as long as vein 1-M.

Legs. Length of hind femur, tibia and basitarsus 3.8, 9.4 and 10.2 times their width, respectively; hind femur (as remainder of leg) with bristly setae; length of outer and inner spur of middle tibia 0.3 and 0.4 times middle basitarsus, respectively; apex of outer side of hind tibia with a cluster of 10 pegs; length of outer and inner spur of hind tibia 0.25 and 0.4 times hind basitarsus, respectively; tarsal claws without lobe.

Metasoma. Length of first tergite 1.6 times its apical width; first tergite sparsely and rather coarsely longitudinally striate, dorsal carinae nearly complete; second tergite sparsely and coarsely longitudinally striate, but smooth medially; remainder of metasoma smooth; ovipositor sheath 1.2 times as long as fore wing, slender.

Colour. Orange brown; propodeum, first metasomal, apical half of third, fourth to eighth metasomal segments, middle coxa, middle trochantellus, most of middle femur, hind coxa, hind trochantellus and hind femur black; hind tibial spurs brown; second and basal half of third tergites ivory dorsally and first-third tergites white ventrally; hind tibia and tarsus dark brown, except yellow basal ring; veins and pterostigma dark brown; apical 0.4 of fore wing distinctly infuscate and remainder of wings slightly infuscate or subhyaline.

Material examined

Holotype: ♀, China, Tibet, Motuo Kadong , 29.32N, 95.32E, 1070 m, 14.V.1980, Jin Gentao & Wu Jianyi, No. 34,201,643 ( SHEM) . Paratype: 1♀, with same data, but No . 34,202,116 ( SHEM).

Distribution

China (Tibet).

Biology

Unknown.

Etymology

From ‘ levis ’ (Latin for ‘smooth’) and ‘ sulcus ’ (Latin for ‘furrow, groove’), because of the smooth precoxal sulcus.

Diagnosis

This new species is very similar to B. albifasciatus (Watanabe) , but differs in having the precoxal sulcus almost smooth (distinctly crenulate in B. albifasciatus ); the malar space about twice as long as basal width of mandible (2.6–2.8 times); and the mesoscutum flattened posteriorly (rather convex posteriorly).

Figures

Figure 4. Bassus levisulcus Tang & Chen, sp. nov. (a) Habitus, lateral aspect; (b) mesosoma, dorsal aspect; (c) head, front aspect; (d) fore wing; (e) mesosoma, lateral aspect; (f) head, lateral aspect; (g) head, dorsal aspect; (h) metasoma, dorsal aspect; (i) hind femur.