The hosts of Nemeritis canescens a problem in the host specificity of insect parasitoids

Published records of the hosts of N.canescens have been collected and critically examined. It is accepted that canescens has developed on twenty‐three species; on one of them perhaps accidentally, on two with some doubt. Twelve species were parasitized in nature; nine species in the laboratory. Two species served as hosts when artificially infected. The natural hosts belong in the Pyralidae, Tinaeidae and Yponomeutidae; the laboratory hosts in the Pyralidae, Oecophoridae and Gelechiidae. One individual was reared from a Tortricid, perhaps accidentally. The host specificity of N.canescens is not easily explained on either a systematic or an ecological basis. It offers interesting problems for research.