A method for rearing the larval stages of the eastern spruce budworm, Choristoneura fumiferana Clemens (Lepidoptera: Tortricidae), for physiological studies

A description is given of an axenic laboratory method for rearing Choristoneura fumiferana larvae that is suitable for physiological studies. The rearing procedure is a modification of the method of D. G. Grisdale (1984), using a wheat-germ based synthetic diet. The axenic rearing method resulted in a larval survival rate, defined as the number of 2nd-instar larvae that survived to the 6th instar (90.9+or-3.4% compared with a larval survival rate of 40.4+or-13.3% obtained by the unmodified method of Grisdale). The survival rate of 6th-instar larvae to the adult stage was about 98% using the axenic method. The development times for larvae using the axenic procedure were 4 days for 2nd-, 3rd- and 4th-instar larvae, 5 days for 5th-instar larvae and 7 (male) or 10 (female) for 6th-instar larvae. These values are in agreement with those reported for larvae reared by the Grisdale method, but a greater degree of development synchrony among larvae was obtained by the modified technique..