Researches on the sensitivity of Hyphantria cunea (Fam: Erebidae) to different bioinsecticides

Fall webworm, Hyphantria cunea (Drury, 1773) (Fam: Erebidae) is one of the important pests of hazelnut in Turkey. The synthetic insecticides are mainly preffered to control this insect in Turkey. The biological control options are very limited. In this study, the effectiveness of six different bioinsecticides (Spintor, Florbac, Biobit, Delfin, Rapax, Rebound) using against other agricultural pests were tested on H.cunea. Thus, it is aimed to increase the biological control options against H. cunea. Their active substances were Spinosad (Spintor), Bacillus thuringiensis aizawai Bonnefoi & de Barjac, 1963 (Florbac) and Bacillus thuringiensis (Bt) kurstaki, Berliner, 1915 (Biobit, Delfin, Rapax, Rebound). They were tested in laboratory and natural conditions. Field trials were conducted in Düzce in 2019. According to data spinosad is the most effective and exhibited highest mortality on different instars of H. cunea. Then comes the strains of Bt aizawai and Bt kurstaki, respectively. At the end of 96 hours in laboratory experiments, spinosad caused 98% death in 2nd and 3rd instars of H. cunea and 83% in 4th and 5th instars. Bt aizawai caused 98% mortality in the 2nd and 3rd instars, 43% of the 4th and 5th instars, Bt kurstaki strains killed 95% of the 2nd and 3rd instars, 51% of 4th and 5th instars. Spinosad also showed the most effective results in field trials. Older larvae were found to be less sensitive in the study. In this study, it was shown that besides Bt kurstaki, bioinsecticides with the active ingredient spinosad and Bt aizawai can also be used against H. cunea.