COMPARATIVE EFFICIENCY OF NEW INSECTICIDE FORMULATIONS AGAINST TOMATO LEAFMINER, Tuta absoluta, MEYRICK (LEPIDOPTERA: GELECHIIDAE) IN EGYPT

Abstract

Tomato plants are the second most important vegetable crop grown in Egypt. Larvae of the tomato leafminer, Tuta absoluta, Meyrick are the most important and destructive pest of tomatoes, capable of causing up to 100% of tomato yield loss in some regions. The effectiveness of chemical control of T. absoluta is limited due to the insect's nature of the damage as well as its rapid capability to develop resistance to various insecticides. A few synthetic pesticides have shown a relative impact in decreasing field populations. However, these synthetic pesticides are not offered at an economically affordable cost to many farmers. Two new formulations with a more affordable cost, designed as Mash-T 15 EC and Mash-V 25 EC were prepared in our laboratory for the control of T. absoluta. Physicochemical properties were in accordance with the FAO/WHO specifications 2010. Bioassay of commonly used pesticides against T. absoluta in Egypt, including Coragen® 20 SC (Chlorantraniliprole), Avaunt® 15 EC (Indoxacarb), and Proclaim®5 WDG (Emamectin benzoate) in comparison with Mash-T and Mash-V against L2/L3 larvae using impregnated romaine lettuce leaves in leaf dipping technique was done. Results support that Chlorantraniliprole was the most effective formulation against T. absoluta larvae, followed by Mash-V. Mash-T and Indoxacarb had moderate activity levels, but emamectin benzoate showed low activity levels at affordable concentrations. Statistical analyses did not detect any significant differences at the LC50 level between Chlorantraniliprole and Mash-V, or between Indoxacarb and Mash-T. However, significant differences were found between emamectin benzoate and other tested pesticides.