Host Effects on Functional and Ovipositional Responses of Bracon hebetor

Publisher Website
Google Scholar
Abstract
(1) This study describes the effects of host species (Anagasta kuehniella (Zeller) and Plodia interpunctella (Hubner)) and size on the ''functional'' and ''ovipostional'' responses of the gregarious parasitoid Bracon hebetor Say, and its preferences between these host types. (2) Attack rates followed a Type II functional response (Holling 1959), with strong interference among parasitoids (Hassel and Varley 1969; Free, Beddington and Lawton 1977). In contrast, both the number of hosts oviposited on per wasp and the number of eggs laid per wasp were essentially independent of host and wasp densities. (3) There were no significant differences in the responses to different sizes of a given host species. There also were not any significant preferences between host sizes, though there was a trend towards preference for the larger, more suitable hosts. (4) The ''handling time'' for A. kuehniella was greater than for P. interpunctella, and there was an active preference for attacking the latter; both results may be due to the defensive writhing of the former species. More eggs were laid on each parastized A. kuehniella, which are larger and so can support more larvae (Taylor 1988), but there were no differences in the numbers of each species oviposited on.

This publication has 0 references indexed in Scilit: