Oviposition behaviour of the polyphagous aphid parasitoid Aphidius colemani Viereck (Hymenoptera: Aphidiidae)

Abstract A population of Aphidius colemani Viereck imported from La Reunion successfully parasitized Aphis gossypii Glover, Myzus persicae Sulzer, Rhopalosiphum padi L., and Toxoptera aurantii Boyer de Fonscolombe in the laboratory. The parasitoid stung, but did not complete development in five other common aphid species. The La Reunion population thus showed a similar host range to Brazilian and other tropical populations of this species, in contrast to the much narrower host range of indigenous Mediterranean populations. In laboratory host-choice tests, a cohort of a Brazilian population of Aphidius colemani reared on Myzus persicae and a cohort reared on Aphis gossypii both preferred to oviposit on Aphis gossypii , indicating an innate genetic preference for this host. However, the cohort reared on Myzus persicae showed a lower degree of preference for Aphis gossypii than the one reared from Aphis gossypii , indicating that epigenetic (conditioning) factors can alter the genetic predisposition to some extent.