The study of the possibility of replacing selective insecticides for sunn pest chemical control and side effect of fenitrothion

The sunn pest ( Eurygaster ineyriceps put.)is the major insect problem of cereal, especially wheat and barley in Iran. The purposes of this project were to evaluate the selective application strategies for insecticides in order to reduce their adverse effects in on IPM programme. Biossay tests of sunn pest of seven insecticides showed that lambda- cayhalothrine and phosalone were the most and least toxic insecides. The experiments have shown that fenitrothion, trichlorphon and synthetic pyrethroids had the RPRC 10 therfor theseinsecticides can be used in concn. reduction and did not getacceptable level of sunn pest contro; in the field. Toxicity of insecticides on developmental stages of T. grandis showed that wasps was the most susceptible stage to insecticides. Parasitized eggs were dipped in solution of insecticides in different developmental stages. The results indicated that diazinon-treated eggs had the lowest emergence percentage (0.09% )and treated with phosalone and primicarb had the highest emergence percentage ( 80% ). Persistence toxicity time tests on the adult of T. grandis showed that trichlorphon with PTT50 7.18 days and Lamhda-cayhalothrine with PTT50 19.8 days minimum and maximum duability among the seven insecticides. studies on effects of insecticides application against overwintered sunn pest revealed that spraying had to significant effects in reducing punctured and damage kernels rate and density of nymphs. However, for reducing the side effects of chemical control on natural enemies, is recommended that in emergency status, trichlorphon should be used against adult overwintered sunn pest after earring stage of wheat. Lambda- cayhalothrine, fenvalerate and trichlorphon were found to be effective on sunn pest in nymphal stage. Among these insectides trichlorphon was the most selective in chemical control of sunn pest ( esp. on Coccinellidae) . Lambda cayhalothrine is recommended for application against sunn pest nymphs because this insecticidehad moderate toxic natural enemies and more toxic on sunn pest nymphs.