Meet the Brown-tail Moth (Euproctis chrysorrhoea)

In the United States, many species of birds prey on the winged adults, including English house sparrow and blue jay.[1] A review of mortality causes in England and mainland Europe described the brown-tail moth as undergoing periodic population outbreaks, each developing rapidly and lasting for several years, followed by a decline to relative obscurity. In a study conducted in England, egg, larvae and pupae deaths were attributed to several parasites, including microsporidia, cytoplasmic and nuclear viruses, and larvae predation by birds, specifically identifying the common cuckoo (Cuculus canorus) and titmice.[14] A more recent review, conducted in Spain, identified 17 species of parasites, viral diseases, unspecified predation and other, unknown, causes of death spanning from eggs not hatching, during summer, winter and spring as larvae, finishing with pupae failing to produce winged adults. Generally, mortality increased with population density, although in outbreak regions there was some compensation by females laying 21.6% more eggs (cause not discussed).[4]