Egg parasitoids of the pine processionary moth and their occurrence in Venosta/Vinschgau

The egg parasitoids of the pine processionary moth Thaumetopoea pityocampa are briefly presented, together with a simplified guide to their morphological identification. Three major, two minor, and three rare species are listed. A few of them occur in the outbreak area of the moth in Venosta/Vinschgau, South Tyrol, Italy, that represents a recent expansion territory for the moth. At the beginning of the outbreak (1999) the parasitoids were not abundant and were manly represented by the generalist species. A sudden increase of egg mortality due to the major specialist Baryscapus servadeii was observed in 2003 and contributed substantially to the natural limitation of the moth populations in the following years. A further increase of parasitism is predicted as long as the host density will remain high, as other potential competitors for the eggs are absent or at very low density.