Development of bisexual attractants for diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae) based on sex pheromone and host volatiles

Males and females of the diamondback moth (DBM), Plutella xylostella (L.) were investigated for electroantennogram responses to 13 volatiles from Brassicaceae in the laboratory, and showed stronger responses to benzaldehyde, phenylacetaldehyde, allyl isothiocyanate, (Z)-3-hexen-1-ol and (Z)-3-hexenyl acetate than to monoterpenic volatiles. In field trapping experiments, traps baited with the synthetic female sex pheromone of DBM+(Z)-3-hexenyl acetate or pheromone+(Z)-3-hexen-1-ol significantly enhanced male catches in three brassicaceous crops, compared with traps baited with synthetic sex pheromone alone. Traps baited with pheromone+(Z)-3-hexenyl acetate and pheromone+(Z)-3-hexenyl acetate+(Z)-3-hexen-1-ol+allyl isothiocyanate enhanced male catches by 46.4% and 75.0%, respectively, compared with synthetic sex pheromone alone, and caught an average of 15.8±2.2 and 18.6±2.7 females/trap/day, respectively, during the whole trapping period. Results indicate that traps baited with pheromone+(Z)-3-hexenyl acetate+(Z)-3-hexen-1-ol+allyl isothiocyanate have a stronger attraction to both male and female DBM and may provide more effective tools for monitoring and controlling this insect pest.