Fall armyworm (FAW), Spodoptera frugiperda, has posed a serious threat to global food security since its discovery in Africa in 2016. Intercropping peanuts with maize is a very common cultivation practice, which can result in a high possibility of peanut damage by FAW. Our study investigated the feeding behavior, plant part preferences, and damage symptoms of FAW larvae on peanuts throughout the larval period, considering changes in population densities and the passage of time over the number of investigations. The results indicated that FAW larvae frequently inhabited peanut leaves, particularly the undersides of the leaves. Larvae moved from the leaves to the soil in the seedling pot to complete development. Furthermore, FAW larvae tended to feed on peanut leaves rather than stems regardless of population densities. Based on the damage symptoms, the feeding preferences of FAW larvae tended to be heart leaves, followed by mature leaves and stems. The most frequent damage symptoms caused by FAW to peanuts were window panes, followed by leafless. This study provides a reference for the integrated management of FAW in peanut fields.
