DEVELOPMENTAL RESPONSE OF 4 SPECIES OF TRICHOGRAMMA (HYM, TRICHOGRAMMATIDAE) TO HEAT SHOCKS

In India, species of Trichogramma oophagous parasitoids against severa l lepidopteran pests have gained importance in the last few years. How ever, the performance of these parasitoids under certain climatic cond itions seems erratic. High temperature prevailing in the sub-continent is suspected to have varying influence on performance of different sp ecies of Trichogramma. To understand the effect of high temperature re gimes we applied heat shocks (35 degrees, 40 degrees and 45 degrees C) for 6 h to all developmental stages of four species of Trichogramma n amely T. chilonis Ishii, T. brasiliensis Ashmead, T. pretiosum Riley a nd T. japonicum Ashmead. Based on two categories, ''A'': to parasitize d host eggs heat shock given for 6 h on the day specified in subscript with A(1), A(2), A(3), A(4), A(5), A(6) and A(7) and ''B'': to parasi tized host eggs heat shock given for 6h from day specified in the subs cript with B (B-3, B-4, B-5 and B-6) onwards till the adult emergence. The results showed that single day heat shock (A series) at 35 degree s C had minimum effect on the developmental biology, adult biofeatures and in the progeny of Thichogmmma. In B series the shock from third d ay onwards till adult emergence seemed to be damaging while the rest w ere safer. However, 40 degrees C proved highly deleterious to Trichogr amma in both A and B series of all species, except T. chilonis which w ithstood heat to some extent.