Pest Management Professional, November 2011

research update Greener approaches By Dr John Klotz Dr Michael Rust Dr Les Greenberg Mark Robertson and Herb Field W ith increasing concern about insecticide use and its environmental fate along with the pest control industrys endorsement of integrated pest management IPM and green technology theres no doubt the need for less toxic and more targetspecific treatments will continue A significant effort in this regard has been the research and development of directed sprays and low toxicity baits for ant control conducted at the University of California Riverside under the leadership of Dr Michael Rust To learn more about this program visit the Urban Pest Ant Management University of California website http groups ucanr org UrbanAnt Links970 which provides various urban ant links including effective low risk pest management strategies that meet customer expectations as well as standard treatments in commercial and residential settings In their 1990 survey The Urban Ants of California with Distribution Notes of Imported Species Rust and Ronald Knight documented the pervasiveness of Argentine ants in California and the challenge they present Argentine ants were more difficult to control than any other species along the California coast and in densely populated areas based on the percentage of retreatments or call backs for each species Evaluation For decades Rusts summer ant program has involved evaluating various experimental techniques and industry standards to control Argentine ant infestations around homes His endeavor is similar to running a pest control route but with the added complication of collecting scientific data about numerous variables including ant population numbers insecticide run off and customer satisfaction For example population monitoring to assess the number of ants is conducted outside homes before and for several weeks after treatment with each treatment replicated at five homes During monitoring 10 sugar water vials are placed next to the house around the outside foundation another 10 are placed away from the house out in the yard Each vial is covered with a flowerpot to prevent disturbance and left in place for 24 hours Then theyre collected and brought back to the laboratory to measure the ants consumption of sugar water Rusts colleague Don Reierson determined an Argentine ant visiting a vial consumes 03 mg of sugar water on average approximately equal to its body weight Using this figure and total consumption one can calculate the total number of ant visits to each vial during the 24 hour monitoring period Researchers are developing lower risk management strategies for ants Evaporative water loss from the vials also is corrected with another set of vials placed outside but protected from ants Efficacy results The experimental treatments are designed to maximize efficacy ant reduction and minimize insecticide run off To achieve this goal the team focused on developing more targeted sprays and baits as standalone treatments and in combination The most effective treatments are those based on an aspect of the ants biology or behavior that results in the distribution of the toxicant throughout the colony spot treating trailing ants with fipronil to optimize its horizontal transfer and using liquid baits to capitalize on liquid food exchange trophallaxis for example Spot treating edges along sidewalks and driveways with as little as 1 gal of Termidor provided the same control level as a general treatment of the property using 3 to 4 gal of Termidor Continued on page 49 32 November 2011 Pest Management Professional mypmp net