Which of the following bugs have piercing sucking mouth parts?

Aphids are classified as having piercing-sucking mouthparts, which they use to extract sap from plants. This adaptation allows them to penetrate plant tissues and feed on the nutrients found in the phloem. Their specialized mouthparts, known as stylets, are particularly efficient for this purpose, enabling them to exploit their plant hosts effectively.

In contrast, the other insects listed do not possess this type of mouthpart. Grasshoppers have chewing mouthparts, suitable for consuming foliage. Caterpillars also have chewing mouthparts that are designed for eating and breaking down leaves. Beetles typically possess hardened mouthparts, also used for chewing. Therefore, the distinctive feeding strategy of aphids sets them apart, making them the correct choice for this question.