Effect of host age on the parasitising potential of four different Trichogramma species

Abstract

The experiment was conducted to determine the effect of host age on parasitising efficacy of four Trichogramma species viz Trichogrammatoidae bactrae, Trichogramma brasiliensis, Trichogramma japonicum and Trichogramma chilonis. Pink bollworm Pectinophora gossypiella (Saunders) was used as host. The host eggs of different ages (1,2,3 and 4 days old) were exposed to four gravid females of the all the four different parasitoid in four glass tubes separately with constant 75% relative humidity and 270C temperature. It was observed that under the conditions of the test all the four species of Trichogramma species showed maximum per cent parasitisation when they were exposed to one day old eggs followed by two days old eggs.