Influence of strain variability and kairomonal substances on parasitization efficiency of Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae)

Trchogramma chilonis Ishii is an effective egg parasitoid for the management of several lepidopterous borer pests. With a view to improve its efficiency further, study was conducted on the influence of strain variability and kairomonal substances on its parasitization under multiple-choice assay using an 8-arm olfactometer. The results revealed that irrespective of treatment with kairomonal substances, highest mean parasitization of Corcyra cephalonica (Stainton) eggs (21.5%) was done by strain collected from the sugarcane borers (Strain IS). Least mean parasitization was observed in eggs exposed to Strain 22. Among the five kairomonal substances tested, hexacosane (0.1%) induced highest mean egg parasitization, The interaction between T. chilonis strains and kairomones indicated that the combination of Strain 15 and hcxacosane (0.1%) was most effective and registered highest egg parasitization (36.6%), followed by the combination of Strain 15 and tricosanc (0.1%). The scope of selecting and utilizing the behaviorally responsive strains in combination with their effective kairomones for field release is discussed.