Photoperiodism in the early balsam strain of the Neodiprion abietis complex (Hymenoptera: Diprionidae).

WALLACE, D. R., and C. R. SULLIVAN. 1974. Photoperiodism in the early balsam strain of the Neodiprion abietis complex (Hymenoptera: Diprionidae). Can. J. Zool. 52: 507-513. The early balsam strain of the Neodiprion abietis complex does not have a photoperiodically controlled, prepupal diapause occurring during the summer in its normal, univoltine life cycle. This is the first Instance we have found in laboratory tests of 15 species and subspecies of diprionid sawflies in which photo hase does not re ulate the course of prepupal development in a normal life cycle. Daylength, [owever, does inhuence the induction of an intense, or ro longed, prepupal diapause that in nature would result in at least a byear life cycle for indivi&alH with the intense diapause. The duration and variability of larval development are both affected by daylength.