Observation on biology and behaviour of flea beetle Phyllotreta cruciferae (Goeze) (Coleoptera Chrysomelidae Alticinae) in Veneto region

Abstract

In six horticultural farms of the Veneto region (in the province of Padua, Venice and Treviso) flea beetles pests of cruciferous crops (cabbage, cauliflower and others cruciferous) are recorded. Monitoring by means of yellow traps and counting of adult specimens on the plants allowed to find the occurrence of five species of Chrysomelidae Alticinae: Phyllotreta cruciferae, P. vittula, P. undulata, Chaetocnema tibialis, C. conducta. Everywhere the most important and most harmful was P. cruciferae. Field observation showed P. cruciferae develops one generation per year. Adults emerge in April, after overwintering in the soil. Mating and oviposition where observed starting from end May to end July. Larvae were found into the soil at the beginning of August. Adults of the second generation emerge on the plants after the mid of August. In October, after climatic condition, they start to reach the soil to overwinter.