Nutritive cost of intraguild predation on eggs of Coccinella septempunctata and Adalia bipunctata (Coleoptera : Coccinellidae)

Coccinella septempunctata was approximately 20% more reluctant to eat the e ggs of Adalia bipunctata than the reverse. In addition, fourth instar larva e of C. septempunctata failed to complete their development on a diet of A. bipunctata eggs and only 30% of those of A. bipunctata completed their dev elopment on a diet of C. septempunctata eggs, and the survivors took nearly 2 times as long as those fed aphids. This is an indication that the costs of intraguild predation might outweigh the benefits.