Studies on Host Selection and Host Specificity of the Aphid Hyperparasite Charips victrix (Hymenoptera: Cynipidae). 2. the Bionomics of Charips victrix

Abstract

The bionomics of Charips victrix (Westwood) when associated with the primary parasites Aphidius smithi Sharma & Subba Rao and Trioxys complanatus Quilis have been examined. This investigation indicates that all developmental stages of A. smithi which occur in nonmummified aphids are attacked. However, only the larval stages are suitable hosts for the development of C. victrix progeny. Several aspects of the development of C. victrix in this host differ from those previously described. Although the development of C. victrix described from T. complanatus is similar to that from A. smithi , the following differences were noted: (1) a few eggs were deposited in the haemocoels of several parasitized and one unparasitized aphid(s), (2) these eggs failed to develop, and (3) T. complanatus embryos were not attacked. Behavioral responses of the spotted alfalfa aphid to C. victrix attacks tend to restrict the ability of the latter to parasitize C. complanatus . A somewhat different behavioral response is observed when the pea aphid is attacked by C. victrix . Both parasitized and unparasitized aphids are investigated by C. victrix females.