Influence of temperature changes in fall armyworm larval development

The fall armyworm (FAW), Spodoptera frugiperda, is one of the most significant pests in agriculture due to its ability to feed on a wide range of crops, including maize, rice, sorghum, cotton, and vegetables. Native to the tropical regions of the Americas, FAW now poses a global threat to cropping systems. FAW moths can migrate long distances or be carried by wind currents, leading to sudden outbreaks that cause devastating crop damage. Recently, FAW survival has been documented in fields at considerably low temperatures, which significantly impacts integrated pest management strategies for this pest. Therefore, this study aimed to determine how stable and oscillating temperature conditions, similar to those in the field, affect the survival and development rate of FAW. This study was conducted in three environments with different temperature conditions: 1) constant high of 25°C, 2) constant low of 16°C, and 3) oscillating temperatures. The oscillating treatment temperatures started at 23°C and decreased to 18°C within a 24-hour period in week 1. Similarly, temperatures started at 18°C and decreased to 15°C in week 2, and from 12°C to 10°C and 10°C to 7°C in weeks 3 and 4, respectively. The results from this study are relevant for optimizing FAW pest management programs and ultimately improving crop production.