Biochemical interaction between chelonine wasps and their lepidopteran hosts: after a decade of research - the parasite is in control

A decade of research on the biochemical interaction between chelonine wasps and their lepidopteran hosts has yielded considerable data on the underlying basis for the developmental, immunological and reproductive effects that these parasites inflict upon their hosts. These egg-larval parasites induce their immunologically compromised host larvae to precociously initiate metamorphosis, followed by suppression of development of the precocious prepupa, in addition to castration of the host. The results from numerous laboratories have shown that the parasite egg that is normally injected by the adult female into the host along with venom, polydnavirus and calyx fluid proteins need not hatch or even be present for the host to exhibit each of these alterations. In addition to these aspects the parasite larva, when present, itself releases hormones and proteins into the hemolymph of the host. A review of the data amassed to date leads inexorably to the conclusion that it is the chelonine wasp that is the biochemically dominant partner. Thus, after 10 years of research, it still appears that in chelonine-lepidopteran parasite-host systems, the parasite is in control of specific points of the biochemistry and development of its host.