Phenological Model for Gypsy Moth, Lymantria dispar (Lepidoptera: Lymantriidae), Larvae and Pupae

A phenological model for gypsy moth, Lymantria dispar (L.), was developed on the basis of 3 yr of laboratory experiments with constant temperature exposures. The model was validated by variable temperature exposures in the laboratory and further validated by field tests at two locations. This model is based upon a simple sigmoid equation for development rate as a function of temperature, and a Weibull function describing distribution of development times of individuals. Host influence on development was incorporated into the model by evaluating previously published works on 10 host species. With required inputs of egg-hatch data and temperatures, the model may be used to predict completion of first through fourth instars, completion of larval development of both sexes, and emergence of adults of both sexes.