The gypsy moth oophagous predator guild in the Mamora forest is an assemblage of many species whose succession in egg masses enhances the exploitation of this food source. Life history, biological Features and trophic capacities of predator species are described from field observations and laboratory rearing. Extreme diversity of diets, capacity to resist prolonged fasting and extended larval development with extra-instars enable them to survive on the cork oak when gypsy moth egg masses are absent. The 1986-1990 gypsy moth outbreak occurred in a forest part where unhealthy cork oaks are common. by providing abundant shelter for numerous arthropods these trees are beneficial to the oophagous predators which find there various and abundant food sources. This probably explains why egg predator activity in the infested area rapidly increased so that the pest outbreak collapsed.