Which term refers to wormlike larva of beetles?

The term that refers to the wormlike larva of beetles is "grub." Grubs are the immature stage of beetles, characterized by their soft, white, and segmented bodies. They typically reside underground or within decaying materials, where they feed and grow before eventually pupating and transforming into adult beetles.

The pupa is a later developmental stage where the larva undergoes metamorphosis to become an adult insect, so it does not specifically describe the larval stage. The term "instar" refers to a developmental stage between molts in insects, including both larval and nymph stages, and is not exclusive to larvae. "Larva" is a general term applicable to many insects and does not specifically denote beetles, thus lacking the specificity that "grub" provides in this context.