Release Rate and Distance Effects of Evaporators with Z-11-Hexadecenal and Z-5-Hexadecene on Disruption of Male Orientation in the Rice Stem Borer Moth, Chilo suppressalis WALKER (Lepidoptera : Pyralidae)

Abstract

In the rice stem borer moth, Chilo suppressalis WALKER, the practical use of evaporators with Z-11-hexadecenal (Z-11-HDAL), major component of the sex pheromone, and its analogue Z-5-hexadecene (Z-5-HD) for disruption of sex pheromone communication was examined in the paddy field. Polyethylene capillary evaporators with Z-11-HDAL at a release rate of 2.1 mg/ha/hr disrupted more than 90% of the male orientation to a virgin female baited trap when placed 16 m apart, and 70% or more disruption occurred at a 64 m separation distance when the release rate from a laminated evaporator was 9.4 mg/ha/hr. These results further suggested that the disruptive effect of Z-11-HDAL may be raised more by an increasing release rate per unit area even if the evaporators are placed more widely apart. The disruptive effect of Z-5-HD on male orientation was apparently lower than that of Z-11-HDAL.