THE INFLUENCE OF OVIPOSITION EXPERIENCE ON RESPONSE TO HOST PHEROMONEIN TRICHOGRAMMA-SIBERICUM (HYMENOPTERA, TRICHOGRAMMATIDAE)

Searching times and residence times of Trichogramma sibericum Sorokina were measured in the laboratory on individual cranberry leaves that h ad been treated with the sex pheromone of blackheaded fireworm [Rhopob ota naevana (Hubner)] and on leaves that were left untreated. Mean sea rching time was higher on leaves treated by passive diffusion with eit her 50 or 100 mu g of the main component of fireworm pheromone, (Z)-11 -tetradecen-1-ol acetate (Z11-14: Ac), than on control leaves. Mean re sidence times were also higher on leaves treated by passive diffusion with 50 mu g of Z11-14: Ac than on leaves untreated with pheromone. Pr etrial oviposition experience in either the presence or the absence of host pheromone did not influence variation in searching time or resid ence time. This indicates that neither associative learning of the odo r of host pheromone nor a more generalized increase in response to che mical stimuli after oviposition (priming) affects retention responses of T, sibericum to pheromone. Results are discussed in the context of current theories on the evolution of learning in insect parasitoids an d as they relate to the concurrent use of pheromone-based mating disru ption and releases of T. sibericum for pest management of the blackhea ded fireworm.