Published online by Cambridge University Press: 10 July 2009
Literature, mainly Indian, pertaining to the recorded hosts of Bracon hebetor Say and B. brevicornis Wesm., and on the taxonomy of the two species, has been reviewed. Observations on different morphological characters, including the male and female genitalia, which have been used in establishing the identity of the two species, have been made. A large number of B. hebetor specimens reared in Bangalore on Corcyra cephalonica (Stnt.), Ephestia cautella (Wlk.), Adisura atkinsoni Moore and those collected in food-grain godowns, and of B. brevicornis reared on C. cephalonica and E. cautella in Bangalore, on Nephantis serinopa Meyr. from Coimbatore (South India), on Pyrausta nubilalis (Hb.) from Canada and on cotton bollworms (?) from Delhi (North India), have been examined.
Differences in colour, relative proportions of antennal joints and punctation on the abdomen have been found to be variable and as such are not to be depended upon for distinguishing the two species. The number of antennal joints which has hitherto been considered to be the decisive character by which the two species may be separated is also not reliable as there is a wide range of variation even in the progeny of a single pair of parents. Above all, the fact that the two species interbreed and give rise to fertile offspring, which also show a fairly wide range of variation in the number of antennal joints, proves that the two are identical, and there is no ground to treat them as two distinct species, at least so far as the Indian specimens are concerned, for which Bracon hebetor Say is the valid name.