Beneficial arthropod behavior mediated by airborne semiochemicals : V. Influence of rearing method, host plant, and adult experience on host-searching behavior ofMicroplitis croceipes (Cresson), a larval parasitoid ofHeliothis.

Rearing the parasitoidM. croceipes on hosts fed cowpea-seedling leaves instead of artificial diet increased the percentage of oriented flights to odors of a cowpea seedling-H. zea complex in a flight tunnel. However, the increase in response was much stronger after adult females had searched a fresh plant-host complex just prior to a test. The host plant appears to be of major importance in the parasitoid-host relationship: host-plant species, growth phase, and part of the host plant influence the parasitoid's response in the flight tunnel. The percentage of inexperienced females responding to infested leaves was higher for 4- to 5-day-old females than for 0- to 1-day-old females, while the response to uninfested flowers was equally high for both age groups. Olfactory experience with odors of an attractive plant-host complex increased the response to an unattractive plant-host complex. Possible implications of the results are discussed.