Orientation to PestPine false webworm, Acantholyda erythrocephala (L.), is an introduced pamphiliid sawfly of European origin that is now present in several parts of eastern North America and Canada. It feeds on several pines. Winter is passed as prepupae, which pupate in the spring. Adults emerge soon after and lay eggs in short rows of 3 to 10 in small slits cut into last year' needles. Young larvae spin loose webs in which they feed gregariously on old needles, which they cut off and then pull into the web to eat. Older larvae are solitary and feed from silken tubes bound to twigs. Frass and bits of needles stick to these silk tubes. When mature, larvae drop to the ground and build the earthen cells and overwinter as prepupae. Heavy infestations can defoliate hosts and cause tree mortality.Hosts Commonly AttackedThis sawfly feeds especially on eastern white (Pinus strobus L.) and red (Pinus resinosa Sol. ex Aiton), but also Scotch (Pinus sylvestris L.), Austrian (Pinus nigra J.F. Arnold), and Japanese red (Pinus densiflora Siebold Zucc.) pines.DistributionThis sawfly is found in New England, New York, New Jersey, Pennsylvania, Wisconsin, Minnesota, Newfoundland, Alberta, Quebec, and Ontario.Biological Control AgentsSince this is an invasive species in North America, the parasitoids from its native range in Europe have been investigated for introduction.The most important such species is the tachinid Myxexoristops hertingi Mesnil, which has been released in Ontario, Canada.