During which part of their life cycle do army worm larvae feed?

Armyworm larvae primarily feed in the early stages of their life cycle, specifically as they first hatch. These larvae are voracious eaters and tend to feed gregariously, which means they often feed in groups. This behavior not only helps them consume a significant amount of plant material quickly but also increases their chances of survival due to the safety in numbers.

In contrast, the other stages mentioned do not involve feeding. During the pupal stage, for example, armyworms undergo metamorphosis and do not consume food as they transform into adult moths. Similarly, when they are still in the egg stage, they are not capable of feeding at all. Once they reach adulthood and develop wings, their primary role shifts to reproduction, not feeding, as adult moths typically do not feed significantly. Thus, the life stage when armyworm larvae actively feed is indeed when they first hatch and engage in gregarious feeding.