Effect of experience on in‐flight orientation to host‐associated cues in the generalist parasitoid Lysiphlebus testaceipes

The effect of experience on the responsiveness of the aphidiid parasitoid Lysiphlebus testaceipes (Cresson) (Hymenoptera: Aphidiidae) to host‐associated cues was investigated using a wind‐tunnel bioassay. Naive females were able to discriminate between uninfested wheat (Triticum aestivum L.) and wheat infested with Schizaphis graminum (Rondani) (Homoptera: Aphididae), but oviposition experience significantly increased the parasitoid's propensity to respond to aphid‐infested plants with upwind, targeted flight. The behavioural change associated with such experience was acquired rapidly (within five minutes) and persisted for at least 24 h. The parasitoid could be successfully conditioned to associate a novel odour with the presence of hosts, suggesting that the increase in response to aphid‐infested plants which occurs as a result of experience is probably due to associative learning of olfactory cues from the plant‐aphid complex.