Bassus albobasalis, van Achterberg, Cornelis & Long, Khuat Dang, 2010

van Achterberg, Cornelis & Long, Khuat Dang, 2010, Revision of the Agathidinae (Hymenoptera, Braconidae) of Vietnam, with the description of forty-two new species and three new genera, ZooKeys 54, pp. 1-184 : 17-19

Bassus albobasalis sp. n. Figs 16-25

Type material.

Holotype, ♀ (RMNH) "S. Vietnam: Dak Lak, Chu Yang Sin N.P., nr dam, 800-1000 m, 2-10.vi.2007, Mal. traps 9-11, C. v. Achterberg & R. de Vries, RMNH’07”. Paratypes (7 ♀): 1 ♀ (RMNH), id., but 800-940 m; 5 ♀ (RMNH, IEBR) "S. Vietnam: Dak Lak, Chu Yang Sin N.P., Krong K’Mar, Mal. traps, 840-940 m or 740-900 m, 2-10.vi.2007, C. van Achterberg & R. de Vries, RMNH’07”; 1 ♀ (RMNH) "N. Vietnam: Thua Thien-Hue, Phong Dien N.R. n[ea]r base-camp, 15 km W Phong My, c 60 m, 22.iii-6.iv.2001, Mal. traps 1-3, C. v. Achterberg & R. de Vries, RMNH’01”.

Diagnosis.

The new species is similar to Bassus lineaticollis (Cameron, 1910) from Sri Lanka, but has the scutellum sparsely finely punctate (in Bassus lineaticollis densely rugulose-punctate) and the first tergite 1.4 times (twice) as long as its apical width. The new species is also similar to Bassus cancellatus (Enderlein, 1920) from China (Taiwan), but differs by having the first and second tergites ivory (black), the body smaller (3-5 mm versus 6-10 mm), fewer antennal segments (29-31 versus 42-46), the first tergite (1.4 times versus 1.7-1.8 times) and the ovipositor sheath shorter (0.7 times versus 1.1 times as long as fore wing). Bassus subrasa (Enderlein, 1920) comb. n. from Indonesia (Sumatra) is similar but has the head dorsally, propodeum, hind coxa and femur brownish-yellow, first and second tergites coarsely striate and the eye about 3 times longer than the temple. Bassus canaliculatus Yang & Chen, 2006, from China (Hubei) has the ovipositor sheath about 1.3 times as long as the fore wing, the dorsal carinae of the first tergite lamelliform and nearly complete, the first tergite with a medio-longitudinal depression and both basal tergites of the metasoma black.

Description.

Holotype, ♀, length of body 5.2 mm, of fore wing 4.6 mm, of ovipositor sheath 3.3 mm.

Head.

Antennal segments 31, length of third segment 1.3 times fourth segment; third, fourth and penultimate segments 3.6, 3.3 and 1.4 times their width, respectively; length of apical segment 1.2 times as long as penultimate segment; length of maxillary palp 0.7 times height of head; malar space 2.7 times as long as basal width of mandible; temple short (Fig. 24), in dorsal view length of eye 4.6 times temple; ocelli in low triangle, POL:OD:OOL = 9:7:18 (Fig. 24); face with distinct fine punctures; frons shiny, smooth; vertex and temple shiny with sparse minute punctures (Fig. 24).

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 mesoscutumsparsely crenulate; lateral and middle lobes of mesoscutum sparsely and distinctly punctate, flat and smooth posteriorly; notauli complete, moderately crenulate anteriorly and narrowly crenulate posteriorly; scutellar sulcus 0.4 times as long as dorsal face of scutellum and with 4 carinae; scutellum slightly convex and distinctly narrowed with lateral carina, shiny with sparse fine punctures, subposterior crest curved (Fig. 17); precoxal sulcus rather deep, moderately crenulate (Fig. 18); mesopleuron below precoxal sulcus with sparse fine punctures; mesopleuron above precoxal sulcus largely smooth; metapleuron with large sparse punctures; propodeum closely reticulate-rugose; propodeal spiracle small, as long as wide.

Wings.

Fore wing: second submarginal cell triangular (Fig. 21); vein SR1 straight; r:3-SR+SR1 = 6:63. Hind wing: vein M+CU 0.6 times as long as vein 1-M (Fig. 21).

Legs.

Length of hind femur, tibia and basitarsus 3.2, 6.8 and 10.0 times their width, respectively; hind femur (as remainder of legs) with bristly setae; length of outer and inner spur of middle tibia 0.3 and 0.5 times middle basitarsus, respectively; apex of outer side of hind tibia with a cluster of 8 pegs; length of outer and inner spur of hind tibia 0.3 and 0.5 times hind basitarsus, respectively; tarsal claws without lobe (cf. Fig. 12).

Metasoma.

Length of first tergite 1.4 times its apical width (Fig. 19); first tergite sparsely and rather coarsely longitudinally striate, dorsal carinae nearly complete; second tergite largely smooth, but transverse groove and area behind it striate; remainder of metasoma smooth (Fig. 19); ovipositor sheath 0.7 times as long as fore wing, slender (Fig. 16).

Colour.

Orange brown; mouthparts yellow; antenna, frons and vertex dark brown; propodeum, third-eighth metasomal segments, hind coxa, trochantellus and femur black; hind tibial spurs yellow; first and second tergites ivory dorsally and white ventrally; hind tibia and tarsus dark brown, except yellow basal ring; veins and pterostigma dark brown, but pterostigma basally narrowly pale brownish; apical 0.4 of fore wing distinctly infuscate and remainder of wings slightly infuscate or subhyaline.

Variation.

Antennal segments 29-31; second submarginal cell of fore wing with vein r-m absent or present; vein M+CU of hind wing 0.6-0.8 times as long as vein 1-M; second tergite with smooth or striate transverse groove; apical segment of antenna 1.0-1.2 times as long as penultimate segment; length of body 3.2-5.2 mm.

Distribution.

C Vietnam: Thua Thien-Hue and S Vietnam: Dak Lak.

Biology.

Unknown.

Etymology.

From “albus” (Latin for “white”) and “basis” (Latin for "foundation, base"), because of the white base of the metasoma.