In India, species ofTrichogramma oophagous parasitoids against several lepidopteran pests have gained importance in the last few years. However, the performance of these parasitoids under certain climatic conditions seems erratic. High temperature prevailing in the sub-continent is suspected to have varying influence on performance of different species ofTrichogramma. To understand the effect of high temperature regimes we applied heat shocks (35°, 40° and 45°C) for 6 h to all developmental stages of four species ofTrichogramma namelyT. chilonis Ishii,T. brasiliensis Ashmead,T. pretiosum Riley andT. japonicum Ashmead. Based on two categories, “A”: to parasitized host eggs heat shock given for 6 h on the day specified in subscript with A1, A2, A3, A4, A5, A6 and A7 and “B”: to parasitized host eggs heat shock given for 6h from day specified in the subscript with B (B3, B4, B5 and B6) onwards till the adult emergence. The results showed that single day heat shock (A series) at 35°C had minimum effect on the developmental biology, adult biofeatures and in the progeny ofThichogramma. In B series the shock from third day onwards till adult emergence seemed to be damaging while the rest were safer. However, 40°C proved highly deleterious toTrichogramma in both A and B series of all species, exceptT chilonis which withstood heat to some extent