Determination of most effective insecticides against maize fall armyworm, Spodoptera frugiperda in South Western Ethiopia

Abstract

ABSTRACTMaize FAWs, S. frugiperda, are economically important pests of maize plants in the field and cause considerable damage of up to 50% in Ethiopia. A total of six insecticides (Malathion 50 EC, Diazinon 48% EC, Alpha-cypermethrin, Deltamethrin, Lambda-cyhalothrin and Dimethoate 40% EC) were tested at laboratory, plot trails (using irrigation System) and farmers maize field (using 3 Delta-type traps) during 2019 to 2020 cropping season. Our result showed that, significant mortality of S. frugiperda was observed in the laboratory bioassay. Alpha-Cypermethrin and Deltamethrin at 24HAT and 72HAT account 76.67% and 100% and 96.67 and 100% of mortality. Highest number of larval mortalities was recorded on the treatment plot treated with Alpha-Cypermethrin (40%) at day one after insecticide application. Dimethoate and Alpha-cypermethrin (5%), Deltamethrin (3.67%) and Lambda-cyhalothrin (7.33%) significantly reduced FAWs infestation at farmers maize farm compared to that of non-treated control group/and plot (27%) at day one after insecticide application respectively. Therefore, the current finding proves that the pyrethroid class of the selected insecticides reduced the damage and infestation level of S. frugiperda in the maize field conditions. Based on the number of maize fall armyworm (the moth group) captured per pheromone traps, the percent of damaged plant and whorl infestations were significantly lowered, and the tools were appropriate to develop IPM programs in Ethiopia.

Keywords

• Maize fall army worm
• Insecticides
• Invasive
• S. frugiperda
• voracious