From Maize to Soybean: How Fall Armyworm Thrives Across Crops

The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a destructive invasive pest that has emerged as a major threat to agricultural production and food security in India. Understanding its biological parameters and feeding behavior on different host plants is essential for developing sustainable pest management strategies. This study assessed the development, survival, and food consumption of S. frugiperda on five crops: maize (Zea mays L.), popcorn (Zea mays everta Sturt), sweet corn (Zea mays saccharata Sturt), sorghum (Sorghum bicolor L.), and soybean (Glycine max L. Merr.).

Life table analysis and consumption rates were modeled using computer simulations. The results indicated that larvae completed development most rapidly on popcorn (28.02 days), maize (28.04 days), and sweet corn (28.31 days), whereas soybean led to the slowest growth (34.83 days). The highest reproductive and population growth rates were recorded on maize, which also supported the greatest food consumption. The sixth-instar larvae consumed a maximum of 19,470.47 mm² of maize leaf area, whereas the lowest consumption was observed on soybean (9,033.67 mm²). Over a simulated 90-day period, population growth was fastest on maize, popcorn, and sweet corn, while soybean restricted development.

Significant larval and pupal survival on non-maize hosts such as sorghum and soybean suggest that S. frugiperda could pose a risk to their cultivation and may impact maize–soybean intercropping systems. Thus, this study highlights the adaptability of S. frugiperda to the tested crops and lays the groundwork for evaluating its potential threat to other intercropping systems.