Interactions of the Asian Lady Beetle, Harmonia axyridis (Coleoptera: Coccinellidae), and the North American Native Lady Beetle, Coccinella novemnotata (Coleoptera: Coccinellidae): Prospects for Recovery Post-Decline.

摘要: The decline of the North American native lady beetle, Coccinella novemnotata Herbst, is strongly correlated with introduction septempunctata L., and C. are locally extirpated across much United States. Since novemnotata's decline, invasive Harmonia axyridis Pallas has become dominant in America. This study investigated whether H. potential to impede recovery populations. To determine how interacts via intraguild predation competition for prey, we paired first-instar at low high densities pea aphid. survival when interspecifically was significantly lower than both aphid densities. Both species had similar weights eclosion densities; however, developed faster novemnotata. examine effect larval size on interactions, conducted a second experiment where varied instar our pairings. final weight increased younger larvae. percentage interspecific treatments, density, same-aged reared conspecifically, except pairs initiated larvae that were two instars more advanced These results suggest prey by have affect populations negatively.