Image: Fly pre-pupa

Fly pre-pupa

Fly pre-pupae - Corpse Fauna

Richard Major
© Australian Museum


Fly pre-pupae and pupae

After the third-instar larva has finished feeding, it moves around in search of a site in which to pupate. For many species, this involves burrowing into the soil. These late, third-instar larvae are called 'pre-pupae' and while they are searching, their skin starts to shorten, fatten and harden, ultimately becoming the pupal case, or puparium.

Carrion fly puparia are brown or black oval structures, about 10 mm in length. Pre-adult flies spend around half their lives as pupae, and this is the stage during which the larval body becomes reorganised into an adult fly. Pupae are resistant to environmental extremes, and in many species, the fly will remain in the puparium until favourable conditions for emergence arise. In some species this means remaining in the puparium over the winter months. Emergence is triggered by environmental changes such as increasing temperature or a rainfall event.

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Tags death, decomposition, insect, fly, diptera, pre-pupa, insects,