Western avocado leafroller, Amorbia cuneana (Walsingham), (Lepidoptera: Tortricidae): Discovery of populations utilizing different ratios of sex pheromone components

The most effective lure for maleAmorbia cuneana (Walsingham) in Orange, Ventura, and Riverside counties of California was previously found to be a 1∶1 ratio of (E,E)-10,12- and (E,Z)-10,12-tetradecadien-1-ol acetates. In subsequent field tests in San Diego and Santa Barbara counties, this lure was ineffective. Analysis of sex pheromone glands (SPG) of femaleA. cuneana from these two counties showed theEE:EZ ratio to be about 1∶9 and synthetic lures of this composition were highly attractive in these areas. Analysis of the SPG of a number of females from both areas showed that there were three population types: two in the low ratio areas possessed 37 and 58%EZ, and the third in the high ratio areas possessed 89%EZ.