Abstract
The efficiency of sex pheromone-baited traps for trapping male Spodoptera litura involves at least two components-attraction efficiency which is concerned with the ability of the trap to attract moths from a distance, and capture efficiency which is concerned with the ability to catch attracted moths. Capture efficiency of box type trap and water-pan trap, both being baited with the sex pheromone blend (litlure, 5mg in a rubber septum), was estimated to be 19% and 17%, respectively, by counting the number of attracted and captured male moths. Male moths were attracted to a trap from a distance in upwind, straight, and level flight, but, at a distance from the trap usually within the range of 2-3m, they reduced the speed of the flight, performing a slow flight as if they were floating. Closer to the trap, forward progression was halted, and after about 10sec more than half of them abruptly flew away. The remainder approached gradually the trap and only a few individuals were occasionally caught in the trap. Although the reason for the poor capture efficiency of the two traps is obscure, both the trap structures and pheromone concentrations do not seem to play a major role.
