Host Finding and Selection bySpalangia drosophilaeAshm.

Abstract

Experiments were designed to determine the criteria by which an ovipositing female ofSpalangia drosophilaeAshm. is attracted to an environment where suitable hosts may be found, and by which these hosts are selected.The results obtained indicate that ovipositing femaleSpalangiaare attracted to and maintained in areas where suitable host puparia may occur by their reaction to sensory impressions. Thus females tend to be attracted to dampness and to soil level where, in grasses, host material is likely to be found. In such an area searching for hosts appears to be at random, but once an object that is a possible host is located there follows a careful examination and, if the object is “ considered ” a suitable host, oviposition follows. It appears that there are several definite criteria by which an object is accepted as a host suitable for oviposition. In general the hosts selected by the parasite are those which are suitable for the development of her progeny.