Efficacy of Bacillus thuringiensis Compared with Some Chemical Insecticides in Controlling Tomato Leafminer, Tuta absoluta (Meyrick)

Tuta absoluta (Meyrick) (Lep.: Gelechiidae) is a major pest of tomato crops that causes high yield losses. Currently, in most countries, T. absoluta management is mainly based on chemical control. Nonetheless, special emphasis is being placed on implementing environmentally safe strategies. Commercial formulations based on Bacillus thuringiensis may be a good alternative, as they have been used to control other insect pests successfully. The laboratory and greenhouse data presented in this work are evidence that B. thuringiensis is highly efficient in controlling T. absoluta. Moreover, the toxicity effect of three pesticides (Biolep, Abamectin, and Indoxacarb) was evaluated against the first and last instar larvae of T. absoluta. Results indicate that the Bt formulation has the highest efficacy compared to the chemical pesticides. Abamectin and Indoxacarb had low mortality effect on the first and last instars of T. absoluta. In conclusion, the Bt formulations are recommended as an effective, environmentally friendly, and safe biopesticide for controlling tomato leafminer.