4 SPECIES OF NOCTUID MOTHS DEGRADE SEX-PHEROMONE BY A COMMON ANTENNALMETABOLIC PATHWAY

Z-9-tetradecenyl acetate (Z-9-14:OAc) is a component in the female sex pheromones of the cabbage looper, Trichoplusia ni (Hubner), beet army worm, Spodoptera exigua (Hubner), fall armyworm, Spodoptera frugiperda (J. E. Smith), and black cutworm, Agrotis ipsilon (Hufnagel). We comp ared the in vivo catabolism of Z-9-14:OAc in time course fashion after the tritiated compound was applied topically to the antennae of males in the four species. Catabolism of tritiated European corn borer, Ost rinia nubilalis (Hubner), sex pheromone (Z-11-14:OAc) was monitored co ncomitantly so direct comparisons could be made between the male borer and the noctuid males. Results showed that catabolism of pheromone in all four noctuid moths proceeded along the same hydrolysis-alcohol ox idation pathway as has been observed in the European corn borer male. Catabolism was mathematically modeled with first-order differential eq uations as a four-compartment degradative system in which tritiated ph eromonal acetate was sequentially converted to tetradecenol, tetradece noic acid and water. The modeling revealed subtle differences in catab olism from one species to another and that most species exhibited a fi nite capacity to catabolize the pheromone.