Field trapping of male Phyllonorycter ringoniella using variable ratios of pheromone components

The sex pheromone of Phyllonorycter ringoniella (Matsumura) (Lepidoptera: Gracillariidae) has been identified to be a blend of (Z)-10-tetradecenyl acetate (Z10-14:OAc) and E4,Z10-tetradecadienyl acetate (E4,Z10-14:OAc) in Japan, Korea, and China. However, the commercial product based on previous results is not attractive enough to be used for monitoring and controlling apple leafminer populations in the field. We re-investigated the attractiveness of the two pheromone components, singly and in blends, in apple orchards in Shangdong and Shaanxi, the main apple-growing provinces in China. Our results revealed that Z10-14:OAc alone was not attractive to P. ringoniella male moths in the field, but E4,Z10-14:OAc alone not only was strongly attractive but caught more males than any of the blends of Z10-14:OAc and E4,Z10-14:OAc tested. The most attractive blend ratios differed slightly for the two locations. No clear dose–response relationship was obtained for the 2:8 blend of Z10-14:OAc and E4,Z10-14:OAc. However, the dose–response field study of E4,Z10-14:OAc alone showed that 1 mg per lure achieved the highest moth catch. These findings differ from the previous report of the best pheromone blend in China. Our data showed that E4,Z10-14:OAc is the major component of the pheromone of P. ringoniella.