Effects of Bacillus thuringiensisvar. kurstaki in combination with henna on three larval stages of tomato borer, Tutaabsoluta (Meyrick) (Lepidoptera: Gelechiidae) in laboratory conditions

The tomato leafminer moth (Tutaabsoluta M.) has been identified as a major pest of Solanaseous especially tomato crops. According to risks of pesticide residue and environmental damage using biological control agents, especially‌Bacillusthuringiensis is considered. In this study, the henna powder was used for enhancing effects. In this research work the interaction between bacterium and henna were assessed by using LC50 and LC25 values of both agents on different larval stages. After determining the LC50 and LC25 values of both agents, to evaluate the combined effects of bacterium and henna, an experiment was conducted in the form of completely randomized design with four treatments including LC50 (He), LC50 (Bt), LC25 (B) plus LC25 (H) and control. The result showed that in three larval stages additive effects was observed; percentage of mortality mixture of bacteria and henna treatments was increased in compare bacteria and henna alone. So that the average mortality in1st larval stage with Henna LC50, bacterial LC50 and LC25 mixture of bacteria and henna, after 24, 48 and 72 h were calculated (20, 26.67and 50), (23.33, 30 and 63.33) and (26.67, 33.33 and 66.67), in 2nd instar larvae (20, 26.67 and 56.67), (23.33, 30, 60) and (26.67, 33.33 and 63.33) and in 3rd instar larvae (20, 23.33and 56.67), (23.33, 30, 60) and (26.67, 33.33 and 63.33) percentage, respectively. Our current study indicated that the integrating B. thuringiensis with henna and other control tactics, especially with environmentally acceptable agents has opened further opportunities for their uses as integrated pest management.