VENOM OF CATOLACCUS-GRANDIS (HYMENOPTERA, PTEROMALIDAE) AND ITS ROLE IN PARASITOID DEVELOPMENT AND HOST REGULATION

The effect of the venom of the ectoparasitoid Catolaccus grandis (Burk s) on boil weevil, Anthonomus grandis grandis Boheman growth, developm ent, and survival, and parasitoid development were investigated. Micro scopic observations showed that 81.4% of parasitized weevils were not paralyzed. The percentage of unparalyzed hosts correlated positively w ith the age of the parasitoid females and negatively with the degree o f superparasitism The growth of envenomed hosts was reduced and enveno med hosts did not complete development. However, parasitoid developmen t was not affected in the absence of venom. The concentration and rati os of free amino acids in the boil weevil haemolymph were significantl y affected by C. grandis venom. Similar changes in free amino acids in bell weevil haemolymph were observed in prepupae not exposed to paras itism, but artificially parasitized by Ist instar C. grandis. The pres ence of a similar envenomizing agent in die Ist instar parasitoids is discussed.