Thaumetopoea pityocampa is the most important pine defoliator in the Mediterranean 24 basin. Despite being attacked by a number of natural enemies, populations occur 25 frequently at high density in several areas. 26 2 Egg parasitism was studied in 27 pine and cedar forests in Algeria, in relation to the host 27 density (tents per tree) and the proportion of forest cover in the landscape. 28 3 Egg parasitism va...