Grub

Definition

The larva of any beetle in the superfamily Scarabaeoidea, characterized by a C-shaped, creamy white body with a well-sclerotized, dark head capsule and three pairs of thoracic legs; typically subterranean and root-feeding.

Etymology

Middle English grubbe, of uncertain origin; related to digging or rooting in soil, reflecting the burrowing habit of these larvae.

Example

The white grubs of June beetles (Phyllophaga spp.) are common turf pests that feed on grass roots, causing brown patches visible during summer drought stress.

Synonyms

• scarab larva
• white grub

Related Terms

• larva
• Scarabaeoidea
• scarab
• white grub
• root-feeder
• C-shaped larva
• sclerotized head capsule

Usage Notes

In entomology, 'grub' specifically denotes scarabaeoid larvae and should not be used for the legless, maggot-like larvae of other beetle families (e.g., Curculionidae) or for caterpillars. The term 'white grub' emphasizes the unpigmented, fleshy abdomen typical of these larvae. In field biology, 'grub' is sometimes used more loosely for any soil-dwelling beetle larva, but this usage is imprecise and best avoided in technical contexts. The C-shaped posture is diagnostic: when disturbed, scarab larvae curl into a tight C, unlike the more linear or loosely coiled larvae of other groups.