This study was carried out to investigate the effect of each single component of the synthetic sex pheromone in the rice green caterpillar, Naranga aenescens and rice leaf roller, Cnaphalocrocis medinalis. Trap catches with each single component or binary mixtures of the sex pheromone in N. aenescens were significantly lower than that with an optimum mixture (2: 1: 4) of Z9-14:Ac, Z9-16:Ac and Z11-16:Ac. But only few number of C. medinalis male was caught in trap baited with each component of the sex pheromone excepting Z13-18:Ald. In an optimum composition of the sex pheromone in C. medinalis, trap catches baited with an 11: 100: 11 mixture of Z11-18:Ald, Z13-18:Ald, and Z13-18:Ac without two alcohol components (Z11-18:OH and Z13-18:OH) was higher than that baited with an optimum mixture of Z11-18:Ald, Z13-18:Ald, Z11-18:OH, Z13-18:OH, and Z13-18:Ac. The efficacy of the sex pheromone lure of N. aenescens kept over 4 weeks. The occurrence of N. aenescens caught in trap baited with sex pheromone gave three peaks and C. medinalis showed two distinct peaks throughout the flight season. Therefore, it can be expected that pheromone-baited trap provides a simple tool for monitoring N. aenescens and C. medinalis in Korea.

This study was carried out to investigate the optimum composition of sex pheromone of the rice green caterpillar Naranga aenescens and its efficacy was examined in a paddy field. The mating rate of N. aenescens tended to be increased with age, showing the highest rate of mating at age 2. The highest mating showed within 1 h after the scotophase, and also mating took place even during the photophase. A GC-EAD analysis of virgin female extracts showed two EAG-active components. Their chromatographic behavior was coincident with that of an authentic sample of Z9-14:Ac and Z11-16:Ac, respectively. The mass spectrum of two EAG-active components was almost identical to that of the authentic samples. The EAG response to two compounds, Z9-14:Ac and Z11-16:Ac, was significantly dose-dependent, but response to Z9-16:Ac was not dose-dependent. A 2: 1: 4 mixture of Z9-14:Ac, Z9-16:Ac, and Z11-16:Ac was the most effective composition for attracting N. aenescens. The male moths increased in proportion to the pheromone amount impregnated. The sticky-typed wing trap baited with sex pheromone captured significantly more males than the other two type of trap examined. Trap catches within a paddy field were much more than those in perimeter trap. The trap-baited with sex pheromone gave three or four distinct fluctuation peaks of male catches throughout the flight seasons.