History of a pine false webworm (Hymenoptera : Pamphiliidae) outbreak in northern New York

A sustained outbreak of pine false webworm, Acantholyda erythrocephala (L.) (Hymenoptera: Pamphiliidae), in northern New York is unprecedented in its extent and duration. White pine, Pinus strobus L., is the preferred host in this region. What began as a 30-ha infestation of this introduced sawfly i n 1981 affected 5440 ha of white pine distributed throughout 231 000 ha in St. Lawrence and Franklin counties by 1995. Occurrence of A. erythrocephala in the United States has been documented in eight northeastern and one nor th-central state (Connecticutt, Massachusetts, Maine, New Hampshire, New Je rsey, New York, Pennsylvania, Vermont, and Wisconsin) and three Canadian pr ovinces (Alberta, Newfoundland, and Ontario). Possible explanations for the occurrence and tenure of the current outbreak in NewYork are discussed.