Natural Enemies of the fall armyworm (Spodoptera frugiperda Smith) and comparing Neem aqueous extracts with its larvae, Gurage zone, central Ethiopia

Abstract

The fall armyworm (Spodoptera frugiperda Smith) is an invasive and polyphagous insect pest. It poses a significant threat to maize crops, uncontrolled infestation can result 100 % loss. However, natural enemies play a vital role in regulating the population of this pest. Additionally, botanical sources extracts have the potential to be effective insecticides. The objectives of the study were to investigate the natural enemies of S. frugiperda in the Gurage zone and to compare efficacy of Neem seed and leaf aqueous extracts with S. frugiperda larvae, central Ethiopia. S. frugiperda larvae and egg masses, cocoons and larvae cadavers collected from infested maze farms. From each round collection 25 healthy and inactive larvae were sampled to rear until emerging adults. Observed predator species recorded. Neem seed and leaf aqueous extracts was tested against S. frugiperda in laboratory condition. The study found a diverse range of natural enemies associated with S. frugiperda, including parasitoids, predators, and entomopathogenic fungi. Three species of parasitoids (Exorista xanthaspis, Tachina spp., and Charops annulipes) were documented in Ethiopia for the first time. Predatory insects belonging to four distinct orders: Hemiptera, Dermaptera, Coleoptera, and Mantodea also identified. In particular, various Hemipterans were observed in the maize farms infested with S. frugiperda. In terms of Neem seed and leaf aqueous extracts, they demonstrated similar mortality rates for S. frugiperda larvae after 72 h, although differences were observed at 24 and 48 h. For effective management of S. frugiperda, more research is needed to fully exploit the potential of natural enemies and botanical source insecticides.

Keywords

• Aqueous extract
• Azadirachta indica
• Natural enemy
• Parasitoids
• Predators
• Tachinid