How do hymenopteran larvae differ from adult insects?

Hymenopterans undergo complete metamorphosis, meaning their larvae are structurally and morphologically distinct from the adults. The differences depend largely on the suborder:12

• Symphyta (e.g., sawflies): These larvae are typically caterpillar-like, possessing a tough head covering, powerfully developed mouthparts, and usually three pairs of thoracic legs along with six or eight pairs of abdominal legs.3
• Apocrita (e.g., bees, wasps, ants): With rare exceptions, these larvae are legless and maggotlike. Their head coverings are softer and thinner than those of Symphyta, and in parasitic forms, the head is often reduced or partially withdrawn into the thorax.3

Compared to adults, hymenopteran larvae generally have poorly developed sense organs, including absent or very small antennae and no ocelli (simple eyes). While adults are characterized by three distinct body regions (head, thorax, and abdomen), two pairs of wings, and specialized mouthparts for biting or sucking, larvae lack wings and fully developed genitalia. Additionally, in most Apocrita larvae, the digestive system remains a blind sac until the final larval stage.34