Occurrence and Dynamics of Arthropod Predators Associated with Fall Armyworm, Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) on Maize in Benin City, Edo State, Nigeria

Abstract

The Fall armyworm (FAW), Spodoptera frugiperda JE Smith recently introduced in Nigeria, is a destructive pest of maize. Safer and more economically beneficial management outcomes have involved biological control constituting the use of predators, parasitoids and pathogens. There is limited information on predators of FAW in Nigeria. A study was therefore carried out in the Benin City, Edo state during the early and late maize cropping seasons of 2019 to identify arthropod predators of FAW on maize, assess their abundance and the relationship between their population and FAW abundance. Sampling was done weekly from the early whorl stage to the reproductive stage of maize plants. Insects collected were preserved using 70% ethanol and identified using morphological keys. Data were subjected to Analysis of Variance (ANOVA) and significant means separated using Duncan Multiple Range test (DMRT). T-test was used to compare predator abundance in both cropping seasons. Predator abundance was correlated with larval abundance using Pearson correlation analysis. The predators recorded in this study included species in the family Formicidae, Forficulidae, Blattellidae, Pentatomidae, and Araneae. Species in the family Formicidae were the most abundant in the early (55.85%) and late (95.67%) cropping seasons. Predator abundance was significantly different (p ˂ 0.001) across the sampling weeks. There was a significant negative correlation between larval abundance and predator abundance in the early season and a significant positive correlation in the late season. This study has provided base line data on some locally existing predators of FAW in Benin City, Edo State, Nigeria.