Olfactory response of ladybird beetle,coccinella septempunctata L. (coccinellidae: Coleoptera) towards aphids and their host plants

The seven-spot ladybird beetle coccinella septempunctata l. is a generalist predator and prefer soft bodied insects. semiochemicals released by the plants in response to herbivorous attack influences third trophic level and natural enemies use these substances to locate their prey. twelve-arm olfactory apparatus was used to evaluate the response of c. septempunctata toward aphids and different host plants of aphids. different horticultural plants and field crops were used singly or in combination with prey as a host. an increased numbers of c. septempunctata was observed when host plants were added with aphids. but was no significant difference in most of the combinations except wheat with aphids (3.8889±0.4554). the fresh leaves of rose,citrus,brassica and wheat (1.2±0.2006,1.3556±0.1416,1.5778±0.1829,2.1444±0.2027,respectively) attracted significantly more numbers of c. septempunctata as compared to control and aphids alone (0.7667±0.1204 and 0.8333±0.1153). with every next hour (3,6 and 12 h) of observation the movement of c. septempunctata toward target localities was elevated. finding of the current investigation revealed that wheat,brassica,citrus and rose infested with aphids can be used as host plants for mass rearing and culture maintenance of c. septempunctata. copyright 2017 zoological society of pakistan.