pupas

Pupae are the life stage between larva and adult in insects that undergo complete metamorphosis, or holometabolism. During this non-feeding stage, larval tissues are broken down and reorganized into adult structures such as wings, reproductive organs, and sensory systems.

Pupation occurs in many insect groups, including Lepidoptera (butterflies and moths), Coleoptera (beetles), Hymenoptera (some bees, wasps, and ants), and Diptera (some flies). Pupae may be free and exposed, enclosed in protective coverings, or formed within a protective case. In butterflies, the pupal stage is often called a chrysalis, a hard or smooth exoskeleton that is part of the metamorphosis; in many moths, the pupa is inside a silken cocoon. Beetles typically have a hard outer shell around the pupa, while many Diptera form a puparium, which is the hardened last larval skin that encases the pupa.

Physiology and development are driven by hormonal signals that halt feeding and initiate tissue remodeling. The duration of the pupal stage varies widely, from a few days to several months, and some species enter diapause, a period of suspended development, in response to environmental cues such as temperature or daylight.

Ecologically, pupae are often immobile and vulnerable to predation, desiccation, and disease, but many employ camouflage, protective coverings, or burial in soil or leaf litter to improve survival. The pupal stage is essential for transforming a larval body designed for feeding into an adult body specialized for reproduction, dispersal, and, in some species, pollination.