Abstract
The tomato borer or the tomato leafminer (TLM), Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) has invaded the Mediterranean basin recently from South America and it is becoming a major global pest of tomato. Additionally, the Egyptian cotton leafworm (ECLW), Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae) is also a serious pest of various economic and non-economic crops in other Mediterranean countries. The excessive use of chemical pesticides is dangerous because these insect pests can develop resistance. The purpose of the present study was to evaluate the efficacy of emamectin-benzoate insecticide against two lepidopterous insects namely; T. absoluta and S. littoralis under laboratory conditions. Laboratory results showed that emamectin-benzoate was effective against larval stages of insects under laboratory conditions. All four concentrations of emamectin-benzoate caused a significant percentage of mortality after 24 hours of treatment as the percentage of mortality increased gradually with time. But almost all concentrations caused 100% mortality of larvae in both species on the 4th and 5th day of treatment. The obtained results showed that there were significant differences between insecticide concentrations, time of exposure and mortality percentage without any adverse effect on the tomato plants.