Temperature Requirements for Development of the Jack Pine Bud worm (Lepidoptera: Tortricidae) and Two of Its Parasitoids (Hymenoptera)

Abstract

Rates of development at various constant temperatures were determined for immature stages of jack pine bud worm, Choristoneura pinus pinus Freeman, and two parasitoids of its overwintering stage, Apanteles fumiferanae (Viereck) and Glypta fumi-feranae Viereck . Jack pine bud worm larvae ( JPB ) required 416 degree-days ( DD ) above 7.5°C for development from emergence of second instars to pupation, while the pupal stage required 129 DD above 8.0°C. The second through the seventh instars required 70.8, 54.5, 55.5, 58.7, 72.8, and 115.3DD above 7.5°C, respectively. Males developed faster than females during the fifth, sixth, and seventh instars, but females developed faster during the pupal stage. This resulted in synchronized emergence of adults of each sex. Parasitism by A. fumiferanae (AF) slowed development of JPB second, third, fourth, and fifth instars by 2.9, 4.2, 11.1, and 24.5 DD above 7.5°C, respectively. JPB parasitized by G. fumiferanae (GF) spent 5.3, 7.1, and 11.3 DD above 7.5°C longer as fourth, fifth, and sixth instars than unparasitized JPB. Larval AF required 352 DD above 7.3°C for development from emergence of second instars to parasite emergence from the host. Pupae required 108 DD above 9.7°C. GF larvae required 485 DD above 6.1°C, and pupae required 167 DD above 7.7°C. These resultssuggestthat parasitism will affect phenology of JPB in the field. Some recommendations for management of JPB populations that consider parasitoid development and conservation of natural enemies are given.