A farmer complains that a large group of caterpillars has just moved into his/her corn field and eaten all the leaves off the plants. What is this pest most likely?

The situation described involves a pest that attacks corn by consuming leaves, leading to significant defoliation. The army worm is renowned for its aggressive feeding habits on a variety of crops, including corn, particularly in the larval stage. These pests typically arrive in large numbers and can strip leaves rapidly, which aligns with the farmer's complaint of a large group of caterpillars.

The fall armyworm is another possibility, as it also feeds on corn, but the term "army worm" generally refers to a group that includes several species, and the army worm is often more commonly recognized. Knowing this, it’s essential to understand that while fall armyworms can also be responsible for similar damage, the broader term "army worm" captures the widespread nature of these pests, reinforcing their reputation for devastating crops.

Cutworms typically affect plants at the base rather than consuming leaves directly, making them less likely to be the primary concern for the problem described. Stink bugs, on the other hand, are known for their piercing-sucking mouthparts and primarily feed on the juices of plants rather than consuming leaves outright.

Thus, considering the feeding behavior and the rapid movement in large numbers, the army worm aligns most closely with the scenario presented, making it the most likely