Bioassays were carried out in Petri dishes with body washings of larvae, male and female moths and scale extract of Corcyra cephalonica St. in hexane to observe their kairomonal effect on Trichogramma brasiliensis (Ashmead) and T. japonicum Ashmead. The mean parasitoid activity index (PAI) and mean parasitisation were recorded. Trichogramma brasiliensis and T. japonicum recorded the highest mean parasitisation in the eggs treated with scale extract. Mean parasitisation recorded by T. japonicum in cards treated with female moth and male moth body washings were considerably lower than the corresponding values for T. brasiliensis. Both the parasitoids recorded significantly lower levels of parasitisation in cards treated with larval body washings. Gas chromatographs of host body washings / extract recorded a large number of similar hydrocarbons in the body washings of male and female moths and the scale extract. Pentadecane, heneicosane, eicosane, tetracosane, pentacosane and hexacosane were recorded in scale extracts. Female moth body washings recorded the presence of eicosane, tetracosane and pentacosane while heneicosane and eicosane were indicated in the male moth body washings.

Studies were conducted to compare adult longevity, number of host eggs parasitized and temporal pattern of oviposition of four species of Trichogramma, T. brasiliensis Ashmead, T. chilonis Ishii, T. minutum Riley and T. japonicum Ashmead. Parasitoids were reared on eggs of Corcyra cephalonica St. at 27 ± 2°C and 60 ± 5% r.h. With the exception of T. chilonis, females lived longer than males. The only thelytokous species, T. brasiliensis had the highest longevity and fecundity. However, T. chilonis was observed to lay more than 50% of its eggs on its first day of emergence. Of the four species, T. japonicum exhibited the shortest longevity and lowest fecundity.