Mortality of the outbreak defoliator Ormiscodes amphimone (Lepidoptera: Saturniidae) caused by natural enemies in northwestern Patagonia, Argentina

Abstract

Outbreaks of the defoliator moth Ormiscodes amphimone are occurring more frequently in numerous Nothofagus forests of Patagonia. However, little is known about the life history of this species including its natural enemies as mortality agents. In this work we quantified mortality by parasitoids and generalist predators at the egg, larval and pupal life stages of O. amphimone in a Nothofagus pumilio (Poepp. & Endl.) Krasser forest in northwestern Patagonia. Parasitism of eggs was relatively low (ca. 11 %), and we did not record significant larval predation by insectivorous birds. However, we recorded elevated mortality caused by larval parasitoids (ca. 50 % in third instar larvae) and pupal predators (ca. 75 %), which suggests that these natural enemies could play a significant role in regulating O. amphimone populations. Our research is an initial step towards understanding the influence of natural enemies on O. amphimone population dynamics. © Sociedad de Biología de Chile.