Apanteles striatus van Achterberg and Ng, 2009

Achterberg, C. van, Hosaka, T., Ng, Y. F. & Ghani, Idris B. A., 2009, The braconid parasitoids (Hymenoptera: Braconidae) associated with seeds of Dipterocarpaceae in Malaysia, Journal of Natural History 43 (11 - 12), pp. 635-686 : 682-684

Apanteles striatus van Achterberg and Ng , sp. nov.

( Figure 9F–J )

Holotype

Female, length of body 2.5 mm, length of forewing 2.9 mm.

Head

Antenna with 18 segments, segments normally densely setose, length of third segment 0.9 times fourth segment, lengths of third, fourth and penultimate segments 2.6, 2.8 and 2.0 times their width, respectively ( Figure 9H ); lengths of maxillary palp 0.6 times height of head; mouthparts not protruding; in dorsal view length of eye 1.4 times length of temple; temple densely and rather coarsely punctate; area behind stemmaticum setose and stemmaticum much wider than high; OOL: diameter of ocellus: POL 5: 3: 6; frons largely smooth, glabrous and nearly flat medially; finely punctate laterally and setose; vertex and clypeus moderately punctate, face rather coarsely punctate, with soft lustre; clypeus rather concave ventrally; eyes densely setose; inner sides of eyes parallel-sided; labrum flat and smooth; malar suture obsolescent; length of malar space 1.2 times basal width of mandible; mandible distinctly twisted apically.

Mesosoma

Length of mesosoma 1.5 times its height; side of pronotum smooth and oblique groove distinct and nearly smooth; propleuron rather convex and punctulate; mesosternal sulcus narrow, rather shallow and smooth; prepectal carina absent; precoxal sulcus weakly impressed posteriorly and smooth; mesopleuron distinctly punctate and setose ventrally and anteriorly, and smooth and glabrous medially and posterodorsally; pleural sulcus finely crenulate; metapleuron smooth, except for some punctures and long setae posteriorly and with deep submedial pit; mesoscutum densely and rather coarsely punctate (interspaces mostly smaller than punctures), also posteriorly and with soft lustre, densely setose; notauli absent; scutellar sulcus damaged by pin but in paratypes narrow, with distinct crenulation; scutellum flat and largely smooth, with few punctures, posteriorly with smooth and strongly shiny band; side of scutellum with narrow crenulate depression, and lunula large and subtriangular; posteriorly narrowly crenulate; metanotum straight anteriorly; antepropodeal suture smooth; propodeum medioanteriorly mainly smooth and coarsely areolate, costulae lamelliform, and no median carina.

Wings

Forewing. r twice as long as 2-SR and hardly differentiated ( Figure 9F ); 2-SR+M about as long as 2-SR; 1-CU1: 2-CU1 5: 8, 1-CU1 oblique and 2-CU1 curved; 1-SR pointing to middle of 1-CU1 ( Figure 9F ); first discal cell somewhat wider than high; 1-R1 about eight times as long as distance of apex of 1-R1 to SR1 ( Figure 9F ); 1-SR+M weakly curved.

Hind wing. r at basal 0.4 of marginal cell; basal cell sparsely setose, less densely than more distal cells; 2-SC+R shortly transverse; M+CU: 1-M 30: 31; cu-a curved, vertical; vannal lobe with fringe and posterior margin partly straight ( Figure 9J ).

Legs

Hind coxa smooth except for some coarse punctures dorsally; tarsal claws normal and setose, without distinct comb, but basally with some bristles; lengths of femur, tibia and basitarsus of hind leg 3.3, 6.5 and 6.3 times their width, respectively; hind tibia without distinct pegs; hind tibial spurs of unequal length, 0.4 and 0.5 times hind basitarsus; fore tarsus rather robust; fore telotarsus without spine; hind femur mainly smooth, punctulate.

Metasoma

Length of first tergite 1.4 times its apical width, parallel-sided, its apical width 2.8 times median length of second tergite ( Figure 9G ), surface of its posterior half distinctly rather curved striate; medial area of second metasomal tergite about four times as wide basally as long and largely smooth, with some punctures and no distinct groove laterally and posteriorly; third and following tergites smooth; length of setose part of ovipositor sheath 0.29 times length of forewing, and 1.1 times hind tibia; ovipositor sheath hardly widened, nearly parallel-sided and gradually narrowed apically ( Figure 9I ); ovipositor very robust and evenly curved and with rather short and weakly attenuated apex ( Figure 9I ); hypopygium of female largely membranous and apically acute.

Colour

Black; palpi and tibial spurs pale yellowish; fore femur (but basally dark brown), tibia and tarsus, base of middle and hind tibiae, apex of middle femur, humeral plate (except dark brown patch), and most of vein C+SC+R brownish-yellow; tegulum, remainder of legs (but coxae black) dark brown, third and following tergites rather dark brown; pterostigma (except for yellowish spot basally) and vein 1-R1 dark brown, remainder of veins unpigmented but veins r, 2-SR and 2-M of forewing brown; parastigma partly brown; wing membrane hyaline.

Variation

Length of body 2.4–2.7 mm, length of forewing 2.9–3.1 mm; the oblique groove of the pronotum nearly smooth to rather coarsely crenulate; length of the setose part of ovipositor sheath 0.29–0.31 times length of the forewing.

Distribution

Malaysia.

Biology

Solitary parasitoid of lepidopterous larvae feeding on seeds of Shorea acuminata Dyer. Andrioplecta shoreae is likely to be the host ( Table 1).

Notes

Belongs to the Apanteles ultor -group ( Nixon, 1965); it runs in the key by Nixon (1967) to the Indo-Australian species to Apanteles baoris Wilkinson, 1930 , but this species has the first metasomal tergite nearly smooth to weakly rugose, pterostigma almost pellucid with a darker border, longer attenuated part of ovipositor, vein cu-a of forewing short, veins 2-CU1 and 1-SR+M straight, vein 2-SR of forewing distinctly differentiated from vein r and first discal cell of forewing less acute anteriorly.

Material examined

Holotype female, ‘‘W. Malaysia, N. Sembilan Pasoh Forest Reserve, coll. 24 January [2002], em. 14 February 2002. From Shorea acuminata seeds, Y.F. Ng and Hosaka’’, ‘‘B 35’’, ‘‘ Shorea acuminata (348310)’’ (UKM). Paratypes (two females): one female, id, but coll. 22 January 2002, no. 324995 and B 36 (UKM); one female, id., but coll. 27 December 2001, em. 6 February 2002, C 27 December 2001 H 6 February 2002, no. 348310 and B 34 (RMNH).

Figures

Figure 9. (A–E) Apanteles hemiaurantius, female, holotype; (F–J) Apanteles striatus, female, holotype. (A, F) Part of forewing; (B, G), first to third metasomal tergites, dorsal aspect; (C, I) ovipositor and its sheath, lateral aspect; (D, H) apex of antenna; (E, J) vein cu-a of hind wing. Scale bars: 1.0×(A, C, E, F, I); 1.3×(B, G, H, J); 2.3×(D).