The Biology of the Parasitic Wasp Mormoniella vitripennis [=Nasonia brevicornis] (Walker)

Abstract

The biology, economic importance, physiology, ecology, cytology, and genetics of the parasitic wasp, M. vitripennis, are reviewed, and its use and value in research are also considered. Normally Mormoniella is an ectoparasite, and uses the pupae of larger Diptera as hosts; at 28''C a generation is completed in 10 days. The species is world-wide in its distribution, and may be found wherever hosts are available. Females are inefficient flyers, and males cannot fly. In genetical research, largely using Sarcophaga pupae as hosts, both spontaneous and radiation-induced mutants have been studied. In the R locus, described in "orthodox" genetic terms as a chromonemal region marked by eye color mutants as well as many other genes, all of which show complete linkage and govern various deleterious traits, including male and female sterility and reduced viability at various stages of the life cycle. Incompatibility in reciprocal crosses is reported to be governed by cytoplasmic factors. The haploid males have 5 chromosomes but little is known about linkage relations or the method of sex determination at present. Dose-action curves by exposing eggs to X-rays and to neutrons, and of treating sperm with X-rays, are reported.