A study of<i>Chrysocharis nephereus</i>(Walker) (Hymenoptera: Eulophidae) and allied species, with observations on their biology in Northern England

Abstract

Summary Morphological variation in Chrysochares nephereus, C. nitetis, C. pentheus and C. laricinellae is examined. A key to the species is provided and their biology discussed. A morphometric analysis of specimens referred to Chrysocharis nephereus (Walker) has revealed the existence of two forms, one of which is here described under the name C. nephereus form betulae. The range of variation in C. nitetis (Walker), C. pentheus (Walker) and C. laricinellae (Ratzeburg) is described, and the latter species is shown to be seasonally dimorphic. A key is provided for the separation of these and allied species. C. novellus (Walker) is synonymised with C. nitetis. Hosts and host food plants of all species are briefly discussed.