What characteristics are key for identifying Water Scavenger Beetle larvae morphology?

Larvae are typically grub-like or caterpillar-like, possess distinct thoracic legs, and often have piercing/sucking mandibles

Identifying the larval stage of water scavenger beetles involves looking at features that differ significantly from the adults. Unlike the larvae of some other aquatic beetles that might be legless, Hydrophilidae larvae generally exhibit a grub-like or caterpillar-like body form, and crucially, they possess distinct legs on their thorax. Furthermore, their specialized predatory diet is supported by distinct mouthparts, typically manifesting as curved, often toothed mandibles designed for piercing prey and sucking out the liquefied contents. The combination of these features, along with the arrangement of their abdominal respiratory structures, aids in distinguishing them taxonomically.