1a. Objectives (from AD-416):
Identify optimal blends and application methods for an attract-and-kill formulation to control citrus leafminer.
1b. Approach (from AD-416):
Field tests using varying rates of pheromone and pesticide in slow-release formulation; effect of treatments on citrus leafminer infestation will be measured.
3. Progress Report:
This project is related to Objective 1: Develop semiochemical-based control methods for citrus pests, particularly Asian citrus psyllid (ACP). Field trials to determine the feasibility of an attract-and-kill strategy for control of the citrus leafminer (CLM) were conducted during 2011 and 2012. Formulations developed by Alpha Scents, Inc. were provided to ARS and collaborators for field evaluation. Proprietary formulations contained the CLM sex pheromone and a toxicant (pesticide). Droplets of the product prototype were applied by hand to trees in an abandoned citrus grove during 2010 and in a planting of 18-month-old citrus seedlings during 2011. No reduction in CLM catch in pheromone-baited traps was observed in the abandoned grove. However, excellent results (reduced trap catch and number of mines) were obtained in treated citrus seedlings. The positive results observed in young citrus plantings is especially encouraging because, as we have shown in other studies, mating disruption is difficult to establish in young groves before canopy closure. Therefore, it appears that mating disruption and attract-and-kill may work in a complementary fashion and may be integrated for more effective control of CLM than would otherwise be possible using one or the other method by itself. Future efforts will address the discrepancy in results during 2010 and 2011 and will attempt to identify the best combination of toxicant and pheromone concentration. During 2012, a field trial was established to determine the longevity of attraction of CLM males by the AlphaScents blend. Traps were baited with a variable number of droplets and deployed in a randomized design and monitored over several weeks. Trap positions were randomly reassigned positions within the grove at each evaluation to minimize variation associated with pest density within the grove. Results are being analyzed and will be provided to AlphaScents.