Field fecundity of the spruce budworm (Lepidoptera: Tortricidae) as determined from regression relationships between egg complement, fore wing length, and body weight

The assumption that the number of eggs laid by a spruce budworm moth in the field is the same as the number laid under laboratory conditions is shown to be false. A method is described for estimating what proportion of the potential fecundity obtained in the laboratory is actually laid in the field. The proportion was shown to range from 0 to 1 for individual females, but averaged between 0.70 and 0.86 for a given population at one locality. Results of this investigation have implications in population dynamics studies of the spruce budworm.