RES Handbook Vol 6 Part 5. Cuckoo-Wasps. Hymenoptera, Chrysididae

Among the British aculeate Hymenoptera, the Chrysididae constitute a spectacularly coloured but little known group of parasitic wasps, commonly referred to as cuckoo-wasps, ruby-tailed-wasps or jewel-wasps. They have a thick and usually heavily sculptured cuticle, richly coloured in brilliant metallic reds, greens, blues and golds. The adults feed at flowers and extra-floral nectaries of plants; the larvae of the British species develop in the cells of solitary bees and wasps, and in the cocoons of sawflies (Hymenoptera). Chrysidid wasps favour bright sunlight and are on the wing from late April to early September, when they can be observed investigating holes in various substrates, the possible nesting sites of their hosts.
D. Morgan
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