Effect of Bacillus thuringiensis endotoxin on Apanteles litae Nixon and Bracon instabilis Marsh. (Hym., Braconidae), two parasitoids of the potato tuber moth Phthorimia operculella Zeller (Lep., Gelishiidae)

: Treatment of the host larvae, P. operculella, with B. thuringiensis did not change their susceptibility to being parasitized by either B. instabilis or A. litae. The longevity of adults of both parasitoids, as well as their egg production, were not markedly affected as a result of the treatment, while the duration of immature stages was prolonged. Also, emergence of the adult parasitoids was significantly reduced. The longevity of emerged adult parasitoids was significantly shortened when fed on honey containing B. thuringiensis and the fertility of the resultant females was significantly reduced.