Instar Development of the Douglas-Fir Tussock Moth in Relation to FieldTemperatures

摘要

Instar development is recorded for the Douglas-fir tussock moth (Orgyia pseudot-sugata) for two different elevations in the Boise National Forest, Idaho, in 1991. The percentage of the population by instars is associated with accumulated degree-days after eclosion, which can be used to predict the proper timing for spray application. For all practical purposes, areas can be released for spraying when third instars are initially found.