Description of a new species of the genus Idiasta Foerster (Hymenoptera: Braconidae) from India

The genus Idiasta Foerster belongs to the Phaenocarpa complex of Alysiinae genera (Fischer 1971; Wharton 1980, 2002) because of the long second flagellomere. The presence of well developed ventral and diagonal ridge in mandibles; 2RS longer than 3RSa; (RS+M) b present; 2CUb arising at or below middle of first subdiscal cell; hind wing with m-cu well developed and M+CU generally equal to or longer than 1M, readily distinguish Idiasta from all other genera in this complex. So far, the genus is represented by 27 species from the world out of which 21 occur in Holarctic region, one in Afrotropical region and five in the Indo-Australian region of which only one Idiasta nigriae (Sharma) occurs in India (described from Himachal Pradesh in 1978) and the Indian subcontinent (Shenefelt 1974; Wharton 1980, 1986 & 2002; Belokobylskij 1998). In the present work a new species, Idiasta transiens, is described. The terminology for the various body parts and wing venation is that of Sharkey & Wharton (1997) while Eady (1968) has been followed for the description of surface sculpture. The types of the new species have been deposited in the Insect collection, Department of Zoology, Aligarh Muslim University, Aligarh, India. Idiasta transiens Samiuddin, sp. nov. (Images 1-5)

The genus Idiasta Foerster belongs to the Phaenocarpa complex of Alysiinae genera (Fischer 1971;Wharton 1980Wharton , 2002) ) because of the long second flagellomere.The presence of well developed ventral and diagonal ridge in mandibles; 2RS longer than 3RSa; (RS+M) b present; 2CUb arising at or below middle of first subdiscal cell; hind wing with m-cu well developed and M+CU generally equal to or longer than 1M, readily distinguish Idiasta from all other genera in this complex.
So far, the genus is represented by 27 species from the world out of which 21 occur in Holarctic region, one in Afrotropical region and five in the Indo-Australian region of which only one Idiasta nigriae (Sharma) occurs in India (described from Himachal Pradesh in 1978) and the Indian subcontinent (Shenefelt 1974;Wharton 1980Wharton , 1986Wharton & 2002;;Belokobylskij 1998).In the present work a new species, Idiasta transiens, is described.
The terminology for the various body parts and wing venation is that of Sharkey & Wharton (1997) while Eady (1968) has been followed for the description of surface sculpture.
The types of the new species have been deposited in the Insect collection, Department of Zoology, Aligarh Muslim University, Aligarh, India.

Etymology
The species name is an arbitrary combination of letters.
Mesosoma: 1.6× longer than high (41:26).Pronotum dorsally with crenulate posterior margin and pronope.Mesonotum emarginate overall, crenulate; notauli short, incomplete, weakly crenulate and deeply impressed anteriorly; mesonotal disc smooth and shiny, largely bare, with few setae on anterior margin and few along in a row of imaginary line of notauli; midpit deep and oval.Scutellum smooth and shiny.Post axillae polished on top, clearly crenulate on bottom.Metanotum smooth, with acute median spine, side field of metanotum finely crenulate.Sternaulus wide, crenulate, extends to mid coxae.Propodeum anteriorly polished with mid longitudinal carina and major part reticulate.
Male: Similar to the female.Host: Unknown.

Remarks
The new species, Idiasta transiens Samiuddin, sp.nov. is closely related to Idiasta nigriae (Sharma) but differs in having: vertex smooth (vertex sparsely punctate in nigriae), mandible tridentate (mandible bidentate in nigriae), F2 twice longer than F1 (F2 shorter than F1 in nigriae), metanotum smooth (metanotum punctate in nigriae); propodeum anteriorly polished with mid longitudinal carina and major portion reticulate (propodeum with a prominent areola and costula, areola interspersed with many transverse carinae and joined by a longitudinal carina to the base in nigriae).