Abstract
The feasibiity of synthetic sex pheromone as a communication disruption agent for the control of the beet armyworm, Spodoptera exigua, was examined by dispensing a 7 : 3 mixture of (Z, E)-9, 12-tetradecadienyl acetate and (Z)-9-tetradecen-1-ol into a 155 ha field containing scattered Welsh onion, Allium fistulosum L., plots (total area : 24 ha). Attraction of male moths to sex pheromone traps in the treated area was completely inhibited throughout the period of the treatment. Densities of egg masses and the 1st and 2nd instar larvae were reduced to 6% and 1%, respectively, relative to those in an untreated are about 9 km away. The maximum density of the 4th and 5th instar larvae was reduced to 4% of that in the untreated area. Consequently, crop damage was drastically reduced. In the treated area, the density of the larvae increased after the removal of the pheromone dispenser in mid-September, contrasting to a decrease of population density in the untreated area. These results showed the efficacy of synthetic sex pheromone in controling field populations of S. exigua.
