LABORATORY STUDY OF THE INTERACTION OF 2 PARASITES OF LYMANTRIA-DISPAR [LEP, LYMANTRIIDAE] - BLEPHARIPA-PRATENSIS [DIPT, TACHINIDAE] AND BRACHYMERIA-INTERMEDIA [HYM, CHALCIDIDAE]

In the laboratory, pupae of Lymantria dispar (L.) parasitized by Blepharipa pratensis (Meigen) were exposed to female Brachymeria intermedia (Nees) to determine whether the females would attack such pupae, and if they did, what was the fate of B. pratensis. B. intermedia did attack parasitized pupae, and B. pratensis survived these attacks about 78% of the time. However, in those cases where B. pratensis appears not to have survived, but B. intermedia did survive, the evidence suggests that the host pupae had not been parasitized by B. pratensis at the time of attack. Field observations also support the conclusion that B. intermedia is not a significant mortality factor of B. pratensis. © 1979 Le François.