Acantholabus HEINRICH, 1974

A. M, 2009, Illustrated key to the tribes of subfamilia Ichneumoninae and genera of the tribe Platylabini of world fauna (Hymenoptera, Ichneumonidae), Linzer biologische Beiträge 41 (2), pp. 1317-1608 : 1488-1489

18. Acantholabus HEINRICH

Acantholabus HEINRICH 1974 - Ann. Zool. Wars. 32 (8): 157-158.

Type species: Acantholabus malaisei HEINRICH.

D i s t r i b u t i o n: Oriental Region ( Burma). 3 species.

I n t r o d u c t i o n:

The genus is close to the genera Platylabus and Dentilabus by form of large and broad thyridia with narrow interval between them and elongated spiracles. With Dentilabus , it is similar due to apophysises and slight impression on interspace between thyridia (at least at Acantholabus malaisei ). It is differed by specific morphology of scutellum.

M o r p h o l o g y:

F l a g e l l u m: Of females slender, bristle-shaped with long basal segments, not widened beyond middle, with white annulus or semiannulus. Flagellum of males with row very distinct elongated tyloides.

H e a d: Head contour rounded with very large eyes and short genae; vertex abrupt just after the ocelli; temples short, behind eyes from above sharply and strongly roundly narrowed backwards and from lateral from strongly, to very strongly downwards; occipital carina from above angularly impressed, but not reach level of eyes and hind ocelli; clypeus strongly convex, slightly separated from middle field of face; mandibles to apex strongly gradually narrowed and carinated.

T h o r a x: Transverse furrow of pronotum not interrupted by keel; pronotal ridge not thickened; pronotal base gradually uniformly curved. Mesonotum strongly convex, only just longer than width, very densely punctured; notauli marked only at basal third; surface of mesonotum with dull structure; subalarum thickened and sharpened; sternauli slightly impressed at front half; scutellum uniformly raised backwards from basal (scutoscutellar) furrow, from above flattened, straightly narrowed backwards and sharply abrupt from apex to postscutellum; carinated laterally and at apex by high sharp carinae, at apex carina interrupted, forming something like teeth. Hind margin of metanotum with teeth. Horizontal part of propodeum in middle distinctly shorter than area posteromedia; area superomedia varies from some wider than length to some longer one, costulae most often indistinct or, if present, situated at middle of area superomedia; areae dentiparae short, of character species with long apophysises, sometimes only with short denticles; coxal carina distinct; spiracles rather large, longish-oval.

L e g s: Very long and slender; hind coxae elongated.

W i n g s: Areolet big, quadrangular, symmetrical; radius almost straight, long; nervulus interstitial. Length of front wing approximately equal to body length or only just shorter.

A b d o m e n:Offemalesfromabove longish-oval, second tergite longer than width at apex, sheath of ovipositor slightly projecting behind apex of abdomen. Petiolus of first tergite rather thick, sharply flattened only at base. Gastrocoeli slightly impressed, long; thyridia large and broad, removed from base of second tergite, interval narrower than breadth each of them with slight impression; 2nd and 3rd tergites from delicate to very delicate punctured or with coriaceous sculpture. Hypopygium from below triangle, without distinct longitudinal fold.

C o l o r a t i o n:Similarto Dentilabus .