Date of this Version
The Canadian Entomologist 100:7 (July 1968), pp. 750–763.
Choristoneura houstonana (Grote) lays eggs singly in July. Egg development ranged from 8 to 11 days, with the majority hatching 10 days after oviposition. Larvae are solitary, and mine during early instars, but later instars feed externally on leaves in shelters made by webbing foliage together. There is one generation each year, and overwintering occurs in a hibernaculum, in mined leaves. Field-collected head-capsule width frequencies indicated nine larval instars. Rearing larvae on seedling junipers indoors indicated a range of 8–11 instars. Pupation occurs during June and July in the shelter where the larva feeds. The pupal stage lasted about 10 days at a constant temperature of 80°F.