Occurrence, bionomics and harmfulness of Crepidodera aurea (Geoffr.) (Coleoptera, Alticidae)

Abstract

The paper deals with the occurrence, bionomics and harmfulness of a flea-beetle Crepidodera aurea (Geoffr.) (Alticidae). The pest was studied at the Bílovice nad Svitavou Forest District (Training Forest Enterprise Masaryk Forest in Křtiny) in the period 2007 to 2010 and in a laboratory. The main host species Populus tremula was about five times more damaged there than Salix caprea. Last year’s beetles occurred on the trees from the beginning of May to the beginning of November (most abundantly at the beginning of June). This year’s (young) beetles occurred from the end of July to the 10th of November (most abundantly in September). Before hibernation, about 1/6 beetles abandoned their earth pupal chambers. The beetles damaged 6.7 cm2 leaves of P. tremula before hibernation (and 14.3 cm2 after hibernation). Females lay on average 194 eggs, namely on the average in 11 clutches at 18 eggs. In the period of the most intensive reproduction (in the second half of May and at the beginning of June), females laid one clutch on average for two days. With the increasing size of females the average number of eggs in ovaries increased as well as their average size. The development was obligatorily univoltine. With respect to the relatively low consumption of food it is not necessary to control the pest. In case of mass outbreak it is possible to control the beetles from the 5th to the 10th of May.