Hyperparasitism and seasonal patterns of parasitism as potential causes of low top-down control in Euproctis chrysorrhoea (Lymantriidae)

Pest suppression is an important ecosystem service provided by biodiversity, though antagonistic interactions may jeopardize its impact on pest suppression. Hyperparasitoids may release herbivore populations from natural enemy pressure and lead to outbreaks directly due to parasitism as well as indirect through behavioural interference. In a previous study we reported that in native populations of Euproctis chrysorrhoea L. (Lymantriidae) primary parasitism was very low and outbreaks were more likely in coastal habitats than inland. Here we hypothesise that hyperparasitoids are the underlying cause of such patterns by reporting data on direct hyperparasitism rates as well as seasonal pattern…