Evaluation of certain neonicotinoid insecticide seed treatments against cereal aphids on some wheat cultivars

Abstract

Field experiment was conducted to find out the comparative efficacy of four commercial neonicotinoid insecticide seed treatments imidacloprid, thiamethoxam, acetamiprid and dinotefuran against cereal aphids, Rhopalosiphum padi L., Schizaphis graminum Rondani, and  Rhopalosiphum maidis Fitch (Homoptera: Aphididae) infesting three wheat cultivars Bani Suef, Sids 1 and Misr 1 at Assiut Governorate, Egypt during 2014/2015 season. R. padi was the most abundant species with an average (62.33, 32.50 and 25.00), followed by S. graminum (28.40, 22.67 and 19.00) and R. maidis (9.17, 8.16 and 6.17aphids/tiller) on the three wheat cultivars respectively. There were significant differences in the number of aphids among the wheat cultivars, Bani Suef, Sids 1 and Misr 1. In early season until the second week of March imidacloprid, thiamethoxam, acetamiprid and dinotefuran seed treatments reduced significantly the aphid population densities. After the second week of March there were no significant differences between all insecticide treatments compared to the untreated control. The application of neonicotinoid insecticides as seed treatments under field conditions to suppress the wheat aphid’s population increased the yield production of wheat cultivars about 23.04–64.98%. In addition, it was an incontrovertible notice that imidacloprid and thiamethoxam seed treatments caused a significant increase in the average yield/feddan in the three wheat cultivars compared to untreated control, whereas acetamiprid and dinotefuran gave a lower increase in the yield production. It might be concluded that, imidacloprid and thiamethoxam had a better efficien­cy against wheat aphids than acetamiprid and dinotefuran. As a result of which, neonicotinoid insecticide seed treatments are an integral component and friendly tactic of integrated pest management programs for aphids control in wheat.