Potential of Aphidius colemani as a vector of entomopathogenic fungiLecanicillium spp.
Abstract: The ability of Aphidius colemani to vector Lecanicillium spp. conidia during hostsearching and/or oviposition to a colony of uninfected Aphis gossypii, and the ability ofA. colemani to discriminate Lecanicillium spp. infected aphid from uninfected individual wasdemonstrated. In bioassays for discrimination ability of A. colemani against fungal infected aphid,there were no significant difference between control plot and Lecanicillium spp. treated plots onthe number of ovipositional behaviours. Only fungus-infected aphids covered with mycelia wereavoided as host insect for oviposition. Results indicate that A. colemani does not have the abilityfor discriminate between healthy and Lecanicillium spp. infected aphids for a period of up to 48hafter infection. In bioassays to assess the fungal vectoring ability of A. colemani to aphidpopulation, the aphid population increased ca. 26 times in control plot during 10 days. Incontrast, aphid population did not increase in plots with A. colemani release up to 8 days afterparasitoid release and then exponentially increase in 10 days. In Lecanicillium treated parasitoidrelease plots, aphid density was maintained at low level up to 10 days after parasitoid release.Considering that the number of mummies of A. gossypii was at the same level in parasitoid andparasitoid + fungi plots, the decrease of the aphid population density might have been an effect ofLecanicillium vectored by A. colemani. In this study, it was revealed that Lecanicillium spp. canact additively to control the aphid by A. colemani vectoring.