Compatibility of jamama oil (Eruca sativa L.) with different stages of Trichogramma chilonis (Ishii) (Hymenoptera: Trichogrammatidae)

Trichograma chilonis (Ishii) is an effective egg parasitoid of lepidopterous pests. It controls pests in eggs stage prior to its damaging to crop. The parasitoid is vulnerable to insecticides or oil sprays applied to the crops. The present study was intended to evaluate the compatibility of Jamama oil (Eruca sativa L.) with T. chilonis under the controlled laboratory conditions. Different Jamama oil concentrations i.e. 1.25, 1, 0.75, 0.5, 0.25% were tested on the different stages of T. chilonis. In pre-oviposition preference of T. chilonis experiment, all the studied parameters including percent parasitism, adult emergence and longevity were found significantly reduced while emergence time significantly increased by all the concentrations of Jamama oil as compared with the control. The results showed that the highest concentration of Jamama oil (1.25%) gave the minimum percent of parasitism, adult emergence and longevity (1, 0.75, 0.5 and 0.25% respectively). Lowest emergence time was recorded by utilizing the lowest concentration of Jamama oil (0.25%) followed by 0.5, 0.75, 1 and 1.25%, respectively. Same trend was also observed in all these parameters in post oviposition of T. chilonis in eggs stage, larval stage and pupal stage by utilizing the different concentration of Jamama oil. In the post oviposition of T. chilonis in adult stage, the highest concentration (1.25%) significantly reduced the adult longevity followed by the lower concentrations respectively. Highest longevity was recorded by using the lowest concentration of Jamama oil (0.5%). These studies showed that Jamama oil adversely affected percent parasitism, adult emergence, emergence time, and longevity of T. chilonis more in the preoviposition stage as compared with the post ovisposition stages of T. chilonis. Moreover, lowest concentrations of Jamama oil were found least toxic to T. chilonis and more effective in terms of percent parasitism, adult emergence, emergence time and longevity of T. chilonis. The results also showed that in the post oviposition stage of T. chilonis, in pupal stage the different concentrations of Jamama oil gave better results in all the studied parameters as compared to all other stages. This shows that Jamama oil can be combined more effectively with the T. chilonis in the pupal stage.