Скачать или смотреть Marsh Fritillary destroyed by parasite

The Marsh Fritillary caterpillar is infected by two wasps, Cotesia bignelli and Cotesia melitaearum. The latter species produces up to three generations, predating a single generation of caterpillars. The first generation attacks the first instar larvae in July and August, killing a percentage of these before pupating, emerging and attacking third or fourth instar caterpillars, spending winter within fourth instar larvae. These infected larvae are killed in spring and the adult wasps infect the final growth stages of the caterpillars. Losses can be so large that a population is wiped out. This removes both the butterfly and wasp from the breeding habitat.

In this footage, newly emerged wasps are spinning their silk webbing within which they will pupate. The white covering delays their emergence until there are newly hatched Marsh Fritillary caterpillars to assault from mid to late July.