Data on the biology of cabbage stem flea beetle, Psylliodes chrysocephalus (Linnaeus, 1758) (Coleoptera, Chrysomelidae, Alticinae).

Biology of Psylliodes chrysocephalus (Linnaeus, 1758) known as pest of rape and other cruciferous crops in Europe was studied under field and laboratory conditions in Western Hungary. Oviposition usually takes place from the end of September through winter until the end of March. The number of eggs laid by a female may nearly be one thousand. The longevity and the rhythm of the oviposition depend on the climatic conditions. In most years the second (L2) and third (L3) developmental stage larvae over winter in the sterns and main ribs of the lower leaves of rape. In gentle winters first (L1) developmental stage larvae can also over winter because oviposition occurs during winter months as well. Adults also over winter, they live until the beginning of April of the next year. The larvae feed inside of the sterns and midribs of rape leaves; moulting also takes place there. At the beginning of May the fully developed larvae leave the plant and enter the soil to pupate. Adults of the new generation appear on the surface by the end of May and begin to feed on green pods of rape but, however, they also chew the leaves and sterns. After the harvest of rape adults are still active. Before going into summer diapause they visit cruciferous crops or various cruciferous weeds for feeding. Summer diapause takes places from the beginning of July until the end of August. On the basis of our investigations Psylliodes chrysocephalus (Linnaeus, 1758) has one generation a year in Hungary.