Biology of pine false webworm (Hymenoptera : Pamphiliidae) during an outbreak

The life history of pine false webworm, Acanthalyda erythrocephala (L.), in three pine (Pinaceae) plantations in northern New York is similar to that reported for this species on red pine, Pinus resinosa Aiton, in Ontario. Ad ult emergence extended from early May to early June. The sex ratio of emerg ing adults favored males by as much as 2.7:1. Oviposition occurred from mid -May to early June. Significantly more eggs per fascicle were deposited on the distal third of branches and in the lower third of the crown. Larval fe eding took place throughout June. The proportion of prepupae remaining in t he soil for more than 1 year varied from 9% to 66% between two sites. There was no evidence of egg parasitism, and egg survival exceeded 95% in each o f 2 years. A new species of nematode (Steinernema sp.) (Nematoda: Steinerne matidae) was recovered from pronymphs. Homaspis interruptus (Provancher) (H ymenoptera: Ichneumonidae) parasitized larvae and emerged from 8.5% and 2.8 % of the pronymphs in two populations.