Effect of conventional insecticides on Trichogrammatoidea bactrae

Under laboratory conditions,effect of 11 kinds of insecticides on Trichogrammatoidea bactrae Nagaraja,an egg parasitioid of Plutella xylostella(L.),were determined.Betacypermethrin,diafenthiuron,avermectins,spinosad,chlorfenapy,fipronil and cartap had the most significant effect on the survival of adults of T.bactrae,and the mortalities of adults were 89.31%-100%,when they were subjected to the toxic film for 8 hours.Diafenthiuron,avermectins and spinosad had the most significant effect on parasitism capacity of adults of T.bactrae,when they were subjected to the toxic film for 1 hours.Chlorfenapy and fipronil were harmful to egg and larva when the parasitized host eggs at different developmental stages(egg,larva,prepupa,and pupa) of T.bactrae were dipped in the insecticidal solutions.The eclosion rate of adults were reduced significantly.However,cartap had an adverse effect on the T.bactrae and resulted in a low emergence rate of nearly 0 on every treated stages.Based on above results,chlorfluazuron,indoxacarb,Bt and tebufenozide were considered safe to T.bactrae,suggesting that these insecticides are compatible to this parasitoid when being used for control of P.xylostella.