Evaluation of Different Management options of Fall Armyworm, (J.E. Smith) (Lepidoptera: Noctuidae) and Assessment of its Parasitoids in Some Parts of Ethiopia

Abstract

The fall armyworm (FAW) is a major pest of maize in America and its outbreaks in 2017 in Africa threatened maize, a staple food crop in the region. The effect of parasitoids, nine synthetic insecticides, eleven botanicals, five entomopathogens and pheromone lures have been studied against FAW in 2017 and 2018. Survey conducted in Jimma, Awash Melkasa, Hawasa, East and West Gojam identified three different species of parasitoids from FAW larvae belonging to Hymenoptera and Diptera. Cotesia icipe (Braconidae) was the dominant larval parasitoid in Hawassa, Jimma and Awash Melkassa with parasitism ranging from 33.8 to 45.3%. Tachinid fly, Palexorista zonata (Tachnidae), was the main parasitoid with 6.4% parasitism in Hawassa whilst, Charops ater (Ichneumonidae) commonly occurred in Jimma with 4.6% parasitism. In laboratory, Karate 5% EC, Radiant 120 SC and Tracer 480SC caused 100% larval mortality 48 and 72hrs after treatment application. In greenhouse experiment, all insecticides significantly reduced foliar damage to maize compared to the untreated check. Among the botanicals tested, Azadirachta indica, Schinnus molle and Phytolacca dodecandra resulted in the highest percentage larval mortality (96-100%) 72 hrs after treatment application. The result of entomopathogenic fungi study also showed Beauveria spp. (APPRC-44BC and B4 strains) and Metarrhizium spp. (APPRC-34 GM strain) highly pathogenic inducing 100% and 80% mortality five days and six days after treatment application, respectively. The trapping experiment showed higher number of male moths in the lure E,7-12 OAC, Z-9-12OAc and Z-11-16OAc. The effective parasitiods, synthetic insecticides, botanicals, entomopathogenic fungi and pheromone lures can be used as a component in an integrated management of FAW under smallholder farmers’ condition in Ethiopia and elsewhere in Africa with further field studies.