Spinosad ve Farklı Bacillus thuringiensis (Bacillaceae) Suşlarının Hyphantria cunea (Lepidoptera: Erebidae) Larvaları Üzerindeki Etkinliğinin Değerlendirilmesi

Abstract

In this study, Bacillus thrungiensis aizawai Bonnefoi & de Barjac, 1963 (Florbac), different isolates of Bacillus thuringiensis (Bt) kurstaki Berliner, 1915 (Biobit, Delfin, Rapax, Rebound) and spinosad (Spintor) were assessed for their efficacy against different instars of Hyphantria cunea (Drury, 1773) (Lepidoptera: Erebidae) under laboratory and field conditions in 2019 in Duzce Province, Turkey. Spinosad was the most effective bioinsecticide, followed by Bt aizawai and Bt kurstaki isolates against various instars of H. cunea. In the laboratory, at 96 hour post-treatment, spinosad caused 98% mortality in 2nd and 3rd instars, and 83% mortality in 4th and 5th instars; Bt aizawai caused 98% mortality in 2nd and 3rd instars and 43% mortality in 4th and 5th instars; and Bt kurstaki isolates caused 95% mortality in 2nd and 3rd instars and 51% mortality in 4th and 5th instars. The results from the field study showed similar trends. The older instars were less susceptible to all the tested bioinsecticides than the younger instars, which may be attributable to the phenomenon known as “maturation immunity”. Bacillus thuringiensis kurstaki has already been recommended for management of this pest. Whereas the data indicated that spinosad and Bt aizawai could also be used as bioinsecticides for control H. cunea larvae.