The effect of five insecticides on the predators Coccinella septempunctata and Hippodamia variegata.

The coccinellids Coccinella septempunctata L. and Hippodamia variegata (Goeze) are two native predators in Greece as well as very important biological control agents against aphids for many crops. The conservation of these predators in IPM approaches requires knowledge of the toxicity and the effects of insecticides on their biological characters. In the present study, the effects of five insecticides (kaolin, mineral oil, insecticidal soap, pymetrozine and imidacloprid) on the mortality, developmental time and consumption of fourth instar larvae of C. septempunctata and H. variegata were studied under laboratory conditions. Kaolin, insecticidal soap and pymetrozine were harmless to the last instar larvae of C. septempunctata and H. variegata whereas imidacloprid was moderate toxic. We concluded that kaolin, insecticidal soap and pymetrozine could be incorporated into IPM programs in combination with the two predator species studied. [ABSTRACT FROM AUTHOR]