The effects of diet upon pupal development and cocoon formation by the cat flea (Siphonaptera: Pulicidae).

Cocoon formation by cat flea larvae was directly related to the quantity of eggs or yeast consumed. Larvae consuming either 1-3 eggs or 0.25-1.0 mg of yeast developed as naked pupae or formed incomplete cocoons. Third instar cat flea larvae fed upon naked pupae and pupae within partial cocoons, but complete cocoons protected pupae from cannibalism. First and second instars did not attack pupae. When larvae were provided with a carpet fiber for protection, a greater number of fleas successfully developed to the adult stage.