Prepupa

Definition

A transitional life stage between the active, feeding juvenile (larva or nymph) and the pupa, characterized by cessation of feeding, reduced mobility, and often behavioral or morphological changes that prepare the individual for pupation. In holometabolous insects, the prepupa typically constructs a pupal cell or cocoon and may show external shortening of the body; in some hemimetabolous groups, it represents a final nymphal instar with suppressed feeding before the terminal molt. The stage is not a true pupa because the insect remains capable of limited movement and has not yet undergone the dramatic reorganization of tissues that defines pupation.

Etymology

From Latin 'prae-' (before) + 'pupa' (doll, pupa), indicating the stage preceding the pupa.

Example

In the cabbage white butterfly Pieris rapae, the final-instar caterpillar ceases feeding, empties its gut, and spins a silk pad before becoming a motionless, contracted prepupa; within hours it molts into the true pupa. In some thrips, the prepupal and pupal stages occur within the soil and are both mobile, blurring the boundary with true pupal immobility.

Synonyms

• pseudopupa

Related Terms

• pupa
• larva
• nymph
• instar
• Pupation
• holometabolous
• hemimetabolous
• Ecdysis

Usage Notes

Specialists distinguish the prepupa from the 'pharate pupa' (the pupa still enclosed in the larval cuticle before ecdysis). The term is sometimes used interchangeably with 'pseudopupa' in literature on certain beetles and thrips, though 'pseudopupa' more often implies a non-feeding, mobile stage that resembles a pupa but retains some juvenile features. In species with cocoon-spinning larvae, the prepupal stage is often brief and easily overlooked; in others, such as some sawflies, it may last days and involve visible color change or behavioral shifts.