Promising new technologies for mating disruption

An attract-and-remove technique eliminates trapped males and requires only a small amount of attractant.

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Attract and remove

The remainder of this article summarizes recent efforts to enhance or develop new mating disruption formulations based on the intriguing results of the cage studies. Attract-and-remove (A&R) technologies appear to offer the possibility of a highly effective option for codling moth disruption. The greatest efficacy of reservoir dispensers should occur when numerous point sources are distributed uniformly within the orchard. They should be designed to release at the minimal rate required for attraction and subsequent deactivation of male response for at least an evening. Reservoir dispensers that are amenable to mechanical application should facilitate achieving this.

The A&R technique offers the advantages of eliminating multiple male orientations and requiring only a small amount of attractant to do so. The lack of enhanced disruption with previously developed attracticidal formulations appears to rest in the inability of moths to consistently make contact with the formulation. A series of flight tunnel studies has subsequently guided us in optimizing technologies for attraction and codling moth removal. The latter can be achieved either by use of a toxicant or by permanently ensnaring the insect. Wind tunnel assays suggest that having a vertical surface upwind of the pheromone source increases time spent near the attractant source. Overall, results suggest that an effective A&R formulation should include an attractant source that maximizes getting moths close to it and some structure that maximizes moth landing. The toxicant or trapping surface will most likely be located on the structure where moths will first land and not the attractant source (lure). Building on this, flight tunnel studies were conducted to identify a highly effective prototype dispenser. The most successful A&R system consisted of a small plastic drinking cup with a band of lambda-cyhalothrin (Warrior, Syngenta) mixed in Vaseline placed around the inside lip (Figure 3). Pheromone was released from a lure hung inside the cup. Moths flown in the wind tunnel were highly attracted to the insecticide-laden cup and 80 to 100 percent of the responders contacted the cup surface. Moreover, brief contact with high and low dosages of Warrior in Vaseline resulted in a high level of mortality for over 130 days.

Moths not obtaining a lethal dose also were greatly impacted. Sublethal doses greatly reduced a male codling moth’s ability to reorient to a female-equivalent pheromone source. We are planning to test several attract-and-remove devices in the coming season and hope to report exciting results in a future article.

 Read more about new pheromone dispensers.