Effect of Bacillus safensis NBRC 100820 isolated from cotton plant against the spiny bollworm, Earias insulana (Boisduval)

Abstract Background Toxic effect of some local bacterial isolates, isolated from the Egyptian cotton plant (Gossypium barbadanceL.), on larvae of the spiny bollworm (SBW),Earias insulana(Boisduval) (Lepidoptera: Nolidae) was studied as well as the biological effects of the most toxic isolate. Results Bacillus safensisNBRC 100820 had the most toxic effect on the SBW larvae compared to other isolates. Larval mortality percentages were 100, 90, 50, 50 and 30% for newly hatched, 3, 5, 7 and 10-day’s old larvae, respectively, after 2 days from treatment. Moreover,B. safensisNBRC 100820 caused latent effects on different stages of SBW. It decreased the larval and pupal weight, percentages of adult emergence and hatchability as well as number of deposited eggs/female more than the control. Using 16s rRNA confirmed the identification ofB. safensisNBRC 100820 and its accession number is MW281809. Conclusions Use ofB. safensisNBRC 100820 can be recommended for biological control ofE. insulana. Further field studies are needed.