Abstract

Two arboreal species of Trichogramma namely, T. embryophagum and T. dendrolimi were evaluated in the laboratory for their efficacy in parasitising the teak defoliator eggs. The parasitoid-host ratio tested were 1: 4, 1: 10 and 1: 20. The percentage parasitism was significantly different between the two parasitoid species and between the three parasitoid - host ratios. However the interaction between the parasitoids and the parasitoid - host ratio was non significant. Parasitism caused by T. embyophagum was significantly higher than that of T. dendrolimi and the highest parasitism occurred under the parasitoid - host ratio of 1: 4. Studies on effect of age of the host egg on their acceptance by the parasitoids revealed that percentage parasitism was significantly higher on fresh eggs than on one day old eggs