Abstract
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.