Effects of the juvenile hormone analog fenoxycarb on various developmental stages of the eastern spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae)

The effectiveness of topical applications of the juvenile hormone analogue fenoxycarb against selected stages of Choristoneura fumiferana was determined. Fenoxycarb prevented eggs at an early stage of embryogenesis (0-24 h old) from hatching, and these eggs were more sensitive to the compound than older eggs (48-72 h old) and larval stages. Fifth-instar larvae displayed lethal morphogenetic effects following fenoxycarb treatment, but 3rd-instar larvae were refractory. Adult females constituted the most sensitive development stage; treated insects laid eggs that failed to hatch. Untreated females that mated with fenoxycarb-treated males laid infertile eggs..