Use of food attractants to monitor and forecast Spodoptera frugiperda (J. E. Smith) seasonal abundance in southern China

Abstract

The fall armyworm (FAW, Spodoptera frugiperda Smith) is an important invasive pest of maize crops in Africa, Asia and the Middle East. To enable timely and effective pest management, accurate monitoring and forecasting of S. frugiperda populations is essential. In this study, we used food attractants to assess seasonal abundance of S. frugiperda in southern Yunnan (China) and determined adult age based upon ovarian development or testes size. During 2020-2021, the seasonal abundance of trapping S. frugiperda males with food attractants and sex pheromones were approximately the same at two eld sites. Both trapping methods yielded S. frugiperda males of different ages -with an identical age structure for both trap types. The proportion of females trapped with food attractants was about 80%, which was signi cantly higher than that of males. S. frugiperda populations at two eld sites were composed of immigrants that either originated in central Yunnan or in eastern Myanmar. Based upon eld-level recordings of adult reproductive state, models reliably anticipated S. frugiperda fecundity dynamics. Next, drawing upon meteorological data and FAW adult age, migration trajectories were established for S. frugiperda immigrant populations. Overall, these novel (food-based) monitoring and forecasting tools can improve integrated pest management (IPM) of S. frugiperda in China and abroad. Key MessageLimited research has been conducted on the role of food-based attractants in S. frugiperda population monitoring.Adult age can be inferred from the reproductive development state of eld-collected male and female S. frugiperda.In southern Yunnan, S. frugiperda adult populations mainly consist of immigrant individuals.Meteorological data and adult age are used to simulating S. frugiperda migration trajectories.These new monitoring and forecasting methods complement the integrated pest management (IPM) toolbox for S. frugiperda.

Migration Activity of Spodoptera litura (Lepidoptera: Noctuidae) between China and the South-Southeast Asian Region

“…The ovarian development status of migratory pests can effectively reflect their population characteristics. Similar to S. frugiperda, local populations typically have lower ovary levels than immigrant populations, especially in migratory corridors [25]. In this study, the ovarian development status of S. litura was classified into five levels according to Zhao et al and Wu et al: the transparent opalescent phase (level 1), yolk deposition (level 2), egg maturation (level 3), the peak oviposition phase (level 4), and the terminal phase (level 5) [26].…”