Monday, December 10, 2007 - 10:29 AM

Impact on aphid species by a native and invasive ant species

B. E. Powell, and Jules Silverman, North Carolina State University, Entomology, Box 7613, Raleigh, NC

Hemipteran honeydew is consumed by many ant species, yet not all Hemipterans are tended and some are preyed upon. Ant-aphid interactions are contingent on the aphid’s ability to elicit tending through optimal honeydew production and the decision making process of tending ants. Colony growth of Invasive ant species is fueled to a large degree by honeydew and aphids tended by these ants often flourish. We hypothesize invasive ants manipulate honeydew resources to gain an advantage over native ants in introduced areas. We demonstrate the differential impact on two aphid species, Aphis gossypii (a myrmecophile) and Myzus persicae (a non-myrmecophile) by a native ant, Tapinoma sessile and an invasive ant, Linepithema humile. We determined in the laboratory that A. gossypii populations were higher when tended by L. humile than T. sessile and that both ant species preyed upon M. persicae under certain conditions. Our results suggest aphids can increase reproductive output with appropriate ant presence and invasive ants provide the stimulus needed for increased aphid resource production.

Species 1: Hymenoptera Formicidae Tapinoma sessile (odorous house ant)
Species 2: Hymenoptera Formicidae Linepithema humile (Argentine ant)
Species 3: Hemiptera Aphidae Aphis gossypii (cotton aphid)