Which insect is primarily known as a pest with a chewing mechanism?

The correct answer is the longhorned beetle, which is known for its distinct chewing mechanism. Longhorned beetles possess powerful mandibles that allow them to chew through woody plant tissues and other organic materials. This characteristic enables them to be particularly damaging to trees and plants, making them significant pests in forestry and agriculture. Their chewing mouthparts are adapted for a diet that often includes bark and wood, which they can damage as larvae when they tunnel into trees.

In contrast, the other insects listed in the choices have different feeding mechanisms. Mealybugs, for example, use specialized mouthparts to siphon sap from plants, which is more of a piercing-sucking mechanism rather than chewing. Mayflies, while they have a significant role in ecosystems, primarily have a different feeding behavior at their adult stage and do not possess chewing mouthparts like beetles. The minute pirate bug is also a predator with piercing mouthparts that feed on small insects or plant juices, rather than a chewing mechanism. Thus, the longhorned beetle stands out for its chewing feeding strategy among the options provided.