Nutrition of the seven-spotted beetles <i>Coccinella septempunctata</i> L. (Coleoptera, Coccinellidae) at different stages of the life cycle

Abstract

The paper presents the results of studies of the seven-spotted beetle ( Coccinella septempunctata L.) life cycle, which has 2 generations in the climatic zone of southern Russia. The main stages of the life cycle are the emergence of imago from winter diapause, the first generation from egg to imago, the second generation from egg to imago, the care of adults for wintering. The eating behavior of coccinellid was studied at each stage of the life cycle, which showed the presence of a small herbivorous period (phytophagous beetles), most of the cycle of the beetles had a predatory lifestyle (entomophage beetles). Experiments in the natural and artificial conditions of studying the nutrition of a seven-point beetle showed that adult beetles were more effective in consuming aphids than the larvae. It was also established that in the natural environment, the degree of palatability, both in the larva and in the imago, was directly dependent on the density of the aphids: as the aphid decreased, the feeding intensity of the beetles decreased. To increase the efficiency of aphid consumption, the joint content of two predatory beetles in the imago stage was used: a seven-spotted beetle ( Coccinella septempunctata L.) and ground beetle ( Tomocarabus bessarabicus concretus Fischer von Waldheim). With such simultaneous use (polyculture), a synergistic effect was observed in their consumption of rosan aphid ( Macrosiphum rosae L.).