an increase in aphid populations was followed by a plague of ladybirds with many reports of people being bitten due to dwindling aphid numbers. During the hot summer of 1976 in the U.K. Assembly is a well known phenomenon in ladybirds which may occur in response to lack of prey or prolonged hot weather. As well as aposematic colouration, ladybirds defend themselves by reflex bleeding and some species are protected by chemical means at various stages of development. Hymenopteran parasites are numerous and generally common. The main predators of ladybirds are birds, frogs, wasps, spiders, dragonflies and other beetles. Some species are thought to lay extra, infertile eggs to provide a back up food source for the larvae when prey are scarce. Two of our UK species, Platynaspis luteorubra (Goeze, 1777) and Coccinella magnifica Redtenbacher, 1843 are associated with ants. Stethorus species are specialist spider mite predators and so are important in biological control. Gut content analysis of apparently specialist predatory species often produces pollen, nectar, honeydew, sap and various fungi. In the absence of sufficient prey coccinellid larvae may predate the larvae of other ladybird species. Coleomegilla maculata DeGeer, 1775, from the U.S.A., is a predator of lepidopteran eggs and larvae. Although most species are noted as aphid and scale insect predators they also take a much wider range of prey larger species attack caterpillars and other larvae. Ladybirds occur in all the main crop producing regions. but their numbers can increase greatly in response to climate or parasite numbers and then they can do severe damage. Some species of epilachninae can be minor pests because they are phytophagous, eating the leaves of grains, potatoes and beans etc. Many have been used in orchards and arable situations as biological control agents. Generally considered useful because many species feed on species of aphid or scale insect which are agricultural or horticultural pests. They are small to medium sized beetles, 0.8-18mm, which are very variable in detail regarding colour and shape but nonetheless very characteristic and recognizable. With more than 5000 described species the ladybirds are a cosmopolitan and generally striking group.
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