Effect of intraguild predation on the survival and development of three species of aphidophagous ladybirds: consequences for invasive species

Abstract 1 Survival and development of hatchling larvae of three aphidophagous ladybirds (Coleoptera: Coccinellidae), Harmonia axyridis Pallas, Coccinella septempunctata brucki Mulsant and Adalia bipunctata Linnaeus, when fed their own and the other species eggs were recorded. 2 In all three species, the larvae survived when fed conspecific eggs. 3 The percentage of larvae of H. axyridis that survived decreased to 35% and 85% when fed eggs of A. bipunctata and C. s . brucki , respectively. All the larvae of A. bipunctata and C. s. brucki died after eating eggs of H. axyridis . None of the larvae of C. s. brucki died after eating eggs of A. bipunctata , whereas 46% of those of A. bipunctata died after eating eggs of C. s . brucki . 4 In general, larvae were reluctant to eat the eggs of other species. However, larvae of C. s . brucki showed less reluctance than H. axyridis to eat the eggs of A. bipunctata . 5 The consequence of this for invasive species of ladybird is discussed.