Biosystematic Studies

Abstract

“Classical” systematics, based on the morphological characteristics of dead adult specimens, cannot provide satisfactory solutions to all the intricate taxonomic problems presented by the species of Aphytis. The identification and separation of Aphytis species are very difficult, owing mainly to the minute size of the species and to the relative scarcity of reliable diagnostic characters. The various species groups contain numerous complexes of cryptic or sibling species, as well as various biological races and other infraspecific entities exhibiting differing degrees of morphological and biological distinctness. In fact, practically every one of the originally described, more common species of Aphytis is now known to include a complex of cryptic forms. The recognition of such forms is, of course, of supreme practical importance for biological control, since they may attack different host species or may otherwise have different inherent capabilities, affecting their efficacy as natural enemies.