The factors responsible for host-finding behaviour in Campoletis chlorideae, a parasitoid of Heliothis armigera [Helicoverpa armigeral, were investigated in the laboratory. When female parasitoids were presented with the leaves of different food plants of their host (pigeon pea (Cajanits cajan), chickpea, tomato, lady's finger [okra], cauliflower and cabbage), all spent time searching, the maximum searching period was on pigeon pea (mean of 96 s) and the minimum on cabbage (54 s). Females would also perform searching behaviour, and some performed stabbing intention movements, when presented with the leaves, flower buds and pods of pigeon pea damaged by 2nd-instar larvae of H. armigera. Intact host larvae, host larval saliva, larval faeces and ether extracts of host larvae also elicited searching movements followed by stabbing intention movements. No stabbing intention movements were performed on healthy parts of pigeonpea plants. Further experiments indicated that it was the odour of the plant and host that was mainly responsible for stimulating the females to perform searching followed by stabbing intention movements. It is concluded that the factors responsible for host finding by C. chlorideae are olfactory rather than visual. none