Laboratory Studies on the Rearing of Aphidius smithi (Hymenoptera: Braconidae) and Its Parasitism of Acyrthosiphon pisum (Homoptera: Aphididae)1

Abstract

The techniques of rearing Aphidius smithi Sharma and Subba Rao on a small laboratory scale, and the factors affecting some aspects of its biology—behavior, mating, oviposition, preimaginal development, and adult longevity—are discussed. In 4-hr parasitization periods with 40 Acyrthosiphon pisum (Harris) on Vicia faba leaves, parasitization by Aphidius smithi was highest (82% average) with first-instar hosts, and declined to 0 with postreproductive aphids. Such differences in percent parasitization were not found in mixed groups of various instars. Progeny production by Acyrthosiphon pisum, ceased after the fourth day if they were parasitized on the first clay of parturition. A. pisum parasitized in the third instar did not mature to the reproductive stage.