Syngaster polychromus, Iqbal & Austin & Belokobylskij, 2006

Iqbal, M., Austin, A. D. & Belokobylskij, S. A., 2006, Systematics of the Australasian endemic wasp genus Syngaster Brullé (Hymenoptera: Braconidae: Doryctinae), Journal of Natural History 40 (13 - 14), pp. 819-853 : 842-843

Syngaster polychromus sp. nov.

( Figures 4b , 5g, h , 6a )

Female

Length. 8.2–8.5 mm.

Colour. Head and pronotum yellow. Scape dark red-brown. Palps yellow. Mesoscutum and scutellum light red-brown. Propodeum milk white with apical margin dark brown. Fore legs yellow with fifth tarsal segment dark brown, mid legs yellow with coxa milk white, tibia light brown, trochanter and tarsal segments dark brown, hind legs dark brown with milk white coxa. First metasomal tergite milk white with dark brown basal and apical margins. Second tergite dark brown with white medio-lateral triangle. Remaining tergites dark brown with rather narrow submedian transverse white stripes.

Head. Width 1.1 times its median length, 1.1 times width of mesoscutum. Head behind eyes weakly convex. Transverse diameter of eye 1.1 times as long as temple in dorsal view. Ocelli medium size, in triangle with base 1.2 times its sides, POL 1.1 times OD, 0.2 times OOL. Frons short and weakly convex. Diameter of antennal sockets 1.8 times distance from socket to border of eye. Eyes glabrous, 1.4 times as high as broad. Malar space height 0.46 times height of eye, almost equal to basal width of mandible. Face width 1.1 times height of eye and almost equal to height of face and clypeus combined. Clypeus without distinct lower flange, clypeal suture distinct. Hypoclypeal depression round, its width 0.8 times distance from edge of depression to eye, 0.4 times width of face. Occipital carina complete, curved ventrally and fused with hypostomal carina. Hypostomal keel wide. Head below eyes convexly narrowed. Maxillary palps about 1.6 times as long as height of head. Antennal flagellum slender, 51–55-segmented, first segment length three times width. Scape more or less compressed, its maximum length including lobe 2.5 times maximum width.

Mesosoma. Length two times its height. Pronotum very short, with distinct submedian pronotal keel. Mesoscutum highly and almost perpendicularly raised above pronotum, its median lobe weakly protruding forward. Notauli deep, narrow, complete, and crenulated. Prescutellar depression rather short, more or less deep, smooth, with five strong carinae, 0.3 times as long as scutellum. Scutellum flat, its maximum width 1.1 times median length. Metanotum with very small median tooth. Subalar depression shallow and wide, rugose-reticulate. Sternaulus very shallow, straight, smooth, running along entire lower length of mesopleuron. Metapleural lobe short and wide. Metapleuron and propodeum fused and surfaces evenly rounded (i.e. propodeal–metapleural suture absent). Propodeum without lateral tubercles, distinctly roundly narrowed from base to apex (lateral view). Fore tibia with very small spines arranged almost in single row. Tarsal segment of middle leg not elongate, basitarsus 3.8 times as long as wide, 2.1 times as long as second segment, fourth segment subsquare. Hind coxa without basoventral tooth, 1.4 times as long as wide. Hind femur 3.4 times as long as wide. Inner spur of hind tibia 1.3 times as long as outer spur, 0.13 times as long as basitarsus. Hind tarsus 0.9 times as long as hind tibia, hind basitarsus 0.95 times as long as second to fifth segments combined, second tarsal segment 0.37 times as long as basitarsus, 1.2 times as long as fifth segment (without pretarsus).

Wings. Length of fore wing 3.57 times its maximum width. Pterostigma 3.7 times as long as wide, 0.82 times as long as R1. 3RSa 1.8 times r, 0.18 times 3RSb, 0.8 times 2RS. Second submarginal cell 1.9 times as long as wide, 0.8 times as long as first subdiscal cell. Hind wing about 5.8 times as long as wide; C+Sc+R almost equal to SC+R.

Metasoma. Metasoma 1–1.1 times as long as head and mesosoma combined. First tergite distinctly and almost linearly widened basally, but weakly narrowed apically, with short and wide basolateral processes, with very small dorsope, without spiracular tubercles, length of tergite almost equal to its maximum submedian width, 1.1 times its apical width; apical width 0.9 times its maximum submedian width, 1.2 times its minimum width. Second tergite with wide and distinctly convex medially basal semicircular area, separated by deep crenulate furrow, median length of area 0.7 times maximum length of tergite, maximum length 0.7 times its basal width, 0.76 times length of third tergite, second suture weakly undulate. Third tergite with distinct straight transverse crenulate furrow in basal one-third. Ovipositor sheaths 0.7–0.75 times as long as body, 1.1 times as long as metasoma, 1.4–1.5 times as long as mesosoma; tip of sheaths slightly clavate.

Sculpture and pubescence. Vertex, frons, and temple entirely smooth. Vertex with rather long semi-erect sparse hairs. Face densely and rather coarsely transversally striate. Sides of pronotum rugulose. Mesoscutum and scutellum smooth. Mesopleuron smooth in most part. Metapleuron sparsely and distinctly punctulate, striate anteriorly, almost smooth posteriorly. Propodeum almost entirely with deep and sparse puncturation, with distinct median carina in basal two-thirds, smooth in apical one-third. Mesoscutum entirely with semi-erect hairs. Hind coxa almost entirely smooth. Hind femur almost smooth. Hind tibia dorsally with very short, dense semi-erect hairs. First tergite with sparse puncturation. Basal area of second tergite densely punctulate, rest of tergite almost smooth. Third tergite in basolateral one-third puncturate. Remaining tergites smooth.

Male

Unknown.

Material examined

Holotype: female, Queensland, 27 ° 20 9 S, 152 ° 46 9 E, Mt Glorious, 10 January , without year and collector ( AEIC) . Paratype: one female, same data as holotype ( AEIC) .

Comments

This species is the only species, other than S. lepidus , to have a vivid white propodeum, and to be found on the Australian mainland. Syngaster polychromus is particularly distinctive and can be separated from all other species based on having the mid and hind coxae white, the metapleuron and propodeum fused and not separated by a distinct suture, the metasoma behind first tergite being mostly white with a black basal band on each tergite, and the face with a distinct median protuberance above the clypeus. This species is named after its distinctive colour pattern.

Figures

Figure 4. (a) Distribution map of Syngaster species in New Guinea: (m) S. crypticus; (´) S. hirtus; (*) S. neoguineensis; (w) S. quadricolor; (&) S. steυensi; (>) S. tricolor; (S) S. υariegatus. (b) Distribution map of Syngaster species in Australia: (>) S. lepidus; arrow, S. polychromus. Map for S. lepidus modified from Austin et al. (1994).

Figure 5. (a, b) Syngaster lepidus Brulle´, female: (a) Propodeum and metasomal tergites 1–3 (dorsal view); (b) propodeum and first metasomal tergite (dorsal view). (c–f) Syngaster neoguineensis sp. nov., female: (c) head (dorsal view); (d) head (frontal view); (e) metasomal tergites 1–4 (dorsal view); (f) propodeum and metasoma (lateral view). (g, h) Syngaster polychromus sp. nov., female: (g) head (anterior view); (h) head, mesosoma and anterior metasoma (lateral view). Scale bars: 1 mm (a, c, d, g); 2 mm (b, e, f, h).

Figure 6. (a) Syngaster polychromus sp. nov., female, propodeum and metasoma (lateral view). (b–e) Syngaster quadricolor (Cameron), female: (b) head and mesosoma (lateral view); (c) head (anterior view); (d) propodeum and first tergite to third tergite (dorsal view); (e) body (lateral view). (f–h) Syngaster steυensi sp. nov., male: (f) head (dorso-lateral view); (g) head (frontal view); (h) propodeum and metasomal tergites 1–2 (lateral view). Scale bars: 2 mm (a, c); 1 mm (b, d–h).