THE SCALE RESPONSE OF TRICHOGRAMMA [HYMENOPTERA, TRICHOGRAMMATIDAE] - VARIATION AMONG SPECIES IN HOST SPECIFICITY AND THE EFFECT OF CONDITIONING

Host specificity and the effect of conditioning on a behavioral response to lepidopteran scales varied among the females of 4 Trichogramma spp. observed in laboratory experiments. Trichogramma species nr Pretiosum Riley and T. exiguum Pinto & Platner responded weakly to Ostrinia nubilalis (Hübner) scales relative to Heliothis zea (Boddie) and Manduca sexta (L.). T. maltbyi Nagaraja & Nagarkatti and T. minutum Riley did not discriminate between scales from these 3 hosts. Conditioning with various combinations of host scales and eggs did not alter host specificity, but in some cases, changed general responsiveness to scales. These were attributed to habituation, loss of appetitive drive due to long oviposition bouts, and associative learning. In general, the scale response seems to be innate and fairly nonspecific. © 1990 Lavoisier Abonnements.