COMPARATIVE TOXICITIES OF THREE INSECTICIDES ON EGGS HATCHABILITY OF Pectinophora gossypiella (SAUNDERS) AND Earias insulana (BOISD.) AND THEIR SIDE EFFECTS ON WASPS OF Trichogramma SPP. (HYMENOPTERA: TRICHOGRAMMATIDAE), UNDER LABORATORY CONDITIONS

 Studies on the toxicity of some new insecticides against Pectinophora gossypiella (Saunders) and Earias insulana (Boisd.) eggs were carried out under laboratory conditions. Field Recommended concentrations (FRCs) of three insecticides viz., Trebon (Etofenprox 30% EC), Cygron (Alpha-Cypermethrin 7% + Flufenoxuron 3% EC), and Raner (Methoxyfenozide 24 SC %) were tested against both eggs of PBW & SBW. Also, persistent toxicity of the tested insecticides was determined against the most susceptible life stage (adult) of three wasps of egg Parasitoid Trichogramma spp., Trichogramma evanescens, Trichogrammatoidea bactrae and Trichogramma brassicae. Results regarding the harmful effects of the insecticides on eggs hatchability of PBW revealed that Trebon caused the highest percentage of mortality (95.52%) followed by Cygron treatment (93.39%), while Raner caused the less percentage of egg mortality (22.35%). There were insignificant differences between mortality percentages caused by insecticides (Trebon& Cygron) and which obtained by Trichogramma evanescens (90.61%). In case of SBW, Trebon caused the highest percentage of mortality (78.7%) followed by Cygron (67.5%) and Raner was the least effective (32.82%) whereas , eggs mortality caused by Trichogramma spp. ranged between(65.72 - 75.1%) with no  differences than those caused by Trebon& Cygron as in case of PBW. On the other hand, Trebon and Cygron showed a strong impact on the tested parasitoids, in contrast Raner was the least one on the tested parasitoids.Regardless of used insecticides, T. evanescens achieved the highest percentage of parasitism (46.53%) compared to 28.82& 20.3l% for T. bactrae and T. brassicae, respectively, whereas, percentage of adult emergence did not differ significantly between the three species of Trichogramma.
On the basis of this study, it could be concluded that Trebon and Cygron   proved highly toxic to the tested pests and showed a strong impact on the tested parasitoids and could not therefore be used in combination with Trichogramma releases, whereas, Raner, is considerably mildly toxic for the pests and less harm for the bio-control agents.