Larviform

Definition

Of or pertaining to an adult organism that retains the external morphology and appearance of a larva, typically due to developmental truncation or neoteny. In insects, larviform females are fully sexually mature yet wingless, often lack adult sclerotization, and may never pupate, while conspecific males develop normal adult features. The condition represents an extreme form of sexual dimorphism linked to reduced mobility and often endoparasitic or sedentary lifestyles.

Etymology

From Latin larva (mask, ghost; later larva) + forma (shape, form), referring to the retention of juvenile body plan.

Example

Female Strepsiptera such as Xenos vesparum are larviform: they remain within the host wasp, never pupate, lack eyes, antennae, and wings, and retain a simplified grub-like cuticle while producing offspring via haemocoelous viviparity.

Synonyms

• larviformous
• larvaloid

Related Terms

• Neoteny
• paedomorphosis
• Sexual dimorphism
• aptery
• Ecdysis
• endoparasitism
• Strepsiptera
• bagworm moth

Usage Notes

Distinguished from general neoteny by the specific retention of larval rather than merely juvenile traits; often implies complete suppression of adult metamorphosis in one sex. Not all wingless females are larviform—true larviform condition requires substantive larval anatomical retention (e.g., soft unsclerotized cuticle, reduced segmentation, absence of imaginal discs). Contrast with 'pupaliform' or 'nymphiform' where adult resembles other developmental stages.