Comparative Susceptibility of Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae) to Common Used Chemical Synthetic Pesticides and Biopesticides in Egypt

Abstract

Tomato plants are the most important vegetable crop grown in Egypt. Larvae of the tomato leafminer, Tuta absoluta, are the most important and destructive pest of tomato, capable of causing up to 100% of tomato yield loss in some regions. Effectiveness of chemical control of T. absoluta is limited due to the insect's nature of damage as well as its rapid capability to develop resistance to diverse insecticides. A few synthetic pesticides have shown relative impact in decreasing field populations. Susceptibilities of L2/L3 larvae of tomato leafminer were assessed to common used chemical synthetic pesticides such as Chlorfenapyr, Imidacloprid, Acetamiprid, Chlorantraniliprole, Indoxacarb and common used biopesticides such as Spinetoram, Abamectin, Emamectin benzoate and Milbemectin under controlled laboratory conditions using impregnated romaine lettuce leaves in leaf dipping technique. Results support that Larvae of Tuta absoluta were highly susceptible to Chlorantraniliprole followed by Chlorfenapyr. However, Moderate susceptibility were shown up toImidacloprid, Acetamiprid, Indoxacarb, Spinetoram and Milbemectin, but slight susceptibility were detected to Abamectin and Emamectin benzoate which showed low levels of activity at affordable concentrations. Statistical analyses did not detect any significant differences at LC50 level between Chlorantraniliprole and Chlorfenapyr as the highly effective ones, or between Spinetoram, Milbemectin as moderate effective biopesticides or among Indoxacarb, Imidacloprid and Acetamiprid as moderate efficient chemical synthetic pesticides. No significant differences were found between Abamectin and Emamectin benzoate as slightly efficient biopesticides. However, significant differences were emphasized between both of them and other tested pesticides.