Published online by Cambridge University Press: 31 May 2012
Spruce budworm weights, either of individuals or of population averages, when related to time, provide more precise measures of development than the usually used time from hibernacula to pupation or to eclosion. For determining or predicting the development stage of field populations, average weights are a more precise alternative to time-consuming, instar determinations. Larvae feed only about 10% of the time, in darkness or light, and the pupal dry weight is 20–24% of the dry weight of artificial diet consumed. Growth curves for laboratory individuals and field populations are described.