Host-Plant Volatiles Enhance the Attraction of Cnaphalocrocis medicals (Lepidoptera: Crambidae) to Sex Pheromone

Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae) is a notorious pest of rice, Oryza sativa L.(Poaceae). Sex pheromone and host-plant volatiles can trap C. medinalis separately. To improve the trap efficiency of sex pheromone, we first tested the synergistic effect of 8 host-plant volatiles, including 2-Phenylethanol, 1-Hexanol, 1-Heptanol, ( Z )-3-Hexenal, ( E )-2-Hexenal, Octanal, Valeraldehyde, and Methyl Salicylate on the attraction of C. medinalis to the female-produced sex pheromone in electroantennography. The addition of ( E )-2-Hexenal, Methyl Salicylate, Valeraldehyde, and ( Z )-3-Hexenal increased electroantennogram response of C. medinalis to sex pheromone. Further testing of the mixtures of these four compounds and sex pheromone in wind tunnel experiments indicated that additive ( E )-2-Hexenal or Methyl Salicylate stimulated the landing behaviors of both male and female C. medinalis compared with sex pheromone alone. Field evaluations showed that mixtures of sex pheromone and ( E )-2-Hexenal or Methyl Salicylate resulted in significantly higher catches to male moths than sex pheromone alone. Using 1:1 and 1:10 combinations of the sex pheromone and ( E )-2-Hexenal, showed a synergistic effect of 95% and 110%, respectively. Furthermore, 1:1 and 1:10 mixtures of the sex pheromone and Methyl Salicylate exhibited a synergistic effect of 69% and 146%, respectively. These results may provide the basis for developing efficient pest management strategies against C. medinalis using host-plant volatiles and insect sex pheromones.