Evaluation the Efficacy of Certain Bio-Rational Insecticides on Tuta Absoluta (Lepidoptera, Gelechiidae) on Tomatoes under Laboratory and Field Conditions

Abstract

The tomato leaf miner (TLM), Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is an exotic pest on tomato plants either in open field or under protected cultivations at Ismailia Governorate and elsewhere. The efficacy of five different commercial bio-rational products viz., Coragen, Dipel 2X, Match, Proclaim and Spinosad in their recommended dose was evaluated against TLM under laboratory and field conditions. Data indicated that under laboratory conditions, the tested insecticides showed various toxicity to first and fourth instar larvae of TLM. Proclaim caused the highest accumulated mortality in TLM larvae, followed by Coragen and Spinosad 10 days post treatment. Dipel 2X and Match were slightly toxic to first instar, while Match didn't show any toxicity towards fourth instar larvae. Under field condition, the lowest number of mines (2.4 mines/plant) was recorded in Coragen treatment after 10 days of application, followed by Proclaim, Spintor, Dipel and Match compared to control at 2.7, 4, 4.1, 9.1 and 9 mines/plant, respectively. The highest percentage of reduction in infestation of TLM was recorded in Coragen, Spintor and Proclaim treatments at 68.33, 61.97 and 54.89%, respectively. Dipel had moderate effectiveness in reduction of infestation at 42.78%, while the lowest percentage of reduction in infestation was recorded in Match treatment at 27.51%.