Management of Fall Armyworm (Spodoptera frugiperda) on Summer Maize in Lebanon

Abstract

Currently, fall armyworm (FAW), Spodoptera frugiperda, is the most important insect pest of maize planted in spring and summer in Lebanon. This led to the excessive use of insecticides to combat FAW using 2 to 3 unsafe pesticides weekly. To save maize crops, a field trial was carried out during the summer of 2023 in the farmers’ field to evaluate environmentally safe and low-risk insecticides recommended by FAO and Lebanese Ministry of Agriculture to combat FAW using data from pheromone traps. The pheromone used was Z-9tetradecenyl acetate (1.96 mg), Z-7dodecenyl acetate (0.02 mg), and E-7 dodecenyl acetate (0.02 mg) produced by Sanidad Agricola ECONEX S.L., Spain. The Trap (unitrap, universal trap) was placed five days after planting in farmer’s field planted with maize cv. Nour on 25 July 2023. Foliar insecticides were sprayed using the recommended dose: 2 sprays with Emamectin benzoate + Alpha-cypermethrin; 2 sprays with Indoxacarb + Alpha-cypermethrin; and one spray with Deltamethrin. The number of captured FAW male and non-FAW moths were counted two times/week starting 31 July 2023. The results obtained showed that the peak of FAW population was during August 22 - September 15. In addition, FAW damage on maize production in the field sprayed with recommended insecticides based on the data from pheromone traps was almost unobservable compared to neighboring farmers’ fields, who followed their own practices. Adjusting planting date and pheromone trap based safe pesticide application is recommended to reduce the impacts of the pest on the quality and quantity of green cobs.