• Madore, Charlene D.
  University of Maine
  
• Boucias, Drion G.
  University of Florida
  
• Dimond, John B.
  University of Maine
  

The experimental insect growth regulator UC-62644 fed at sublethal concentrations to 6th-instar spruce budworm, Choristoneura fumiferana (Clemens), caused a dose-dependent reduction in reproduction potential of emerging adults. At 0.01 ppm, there were no effects on mating, fecundity, or hatch. Reciprocal crosses between adults from the control and 0.025-ppm treatment demonstrated that males were more susceptible to UC-62644 than females. At this concentration, the UC-62644 reduced their capability to successfully mate with either treated or control females. The few females that were mated by males from the 0.025-ppm treatment produced normal complements of viable eggs. Higher concentrations (0.034 ppm) of UC62644 affect both sexes. Reduction in mating success was greater in treated males, and reductions in egg production was significant only with treated females.