Adaptive performance of Trichogramma chilonis Ishii at low temperature

The low temperature adapted strain of Trichogramma chilonis was developed after rearing for 30 generations under laboratory conditions at 18–24°C with 95.0±0.44% parasitism. The development, searching ability and biological parameters of low temperature (18–24°C) adapted strain of T. chilonis was studied in comparison with the strain reared in the laboratory at ambient temperature, with a view to utilize them in cooler months. Non-significant variation among adapted and nonadapted strain was observed with respect to % parasitism, fecundity and longevity when reared in small glass vials. However, in the cage studies for parasitoid's searching ability, 58% eggs were parasitized by the low temperature adapted strain as compared to 17.2% by the non-adapted strain. The host searching test indicated that adaptation at low temperature led to better host searching and such strain could be successfully utilized under a low temperature regime.