Ecological Relationships Among Parasites of Spodoptera praefica 12

Abstract

Three species in the native parasite guild of Spodoptera praefica (Grote) account for 95% of the apparent mortality due to parasitization of host larvae in hay alfalfa. In field studies, parasitization did not decrease when 1, 2, or 3 parasite species were reared from hosts occurring in the same subsample. Laboratory studies indicate that intrinsic competitive ability and an index of potential reproductive capacity are inversely correlated among the 3 species. Comments are presented on the utility of the concept of r- and K- selection and the practice of releasing more than one species in biological control.