[Tech Talk] Optimizing Bait Formulations

Throughout the summer of 2015, PCT magazine delivered outstanding content on using bait formulations for a variety of pests. In the May issue, there was a section dedicated to the 20_year anniversary of Sentricon and a “State of the Ant Market” report sponsored by Syngenta. In the June issue, several articles and advertisements discussed a similar strategy on the use of lures.

Although sometimes used interchangeably, there is a difference between “bait” and “lure” depending on the application. The use of pheromones for stored product pests, and specific host compounds to attract bed bugs, would be examples of lures designed to attract and capture a pest. Baits, on the other hand, are formulated to attract a pest, but are then meant to be consumed by the pest.

In July, PCT also published valuable information regarding the success of multiple baiting strategies for one of our top pests: cockroaches. It also included a feature on bait rotation.

The detailed editorial coverage revealed the significant impact of bait applications to our industry, with multiple articles and surveys showing an overwhelming preference of pest professionals to utilize some form of bait as their primary control method. If you are experiencing bait failures, or if you simply want to improve your success with these formulations, some of the technical findings below may be of assistance:

• Set reasonable expectations with the customer — baits may take longer to gain control, but will often lead to a more permanent solution. Avoid the pressure of switching strategies mid-stream; it’s costly and could lead to further delays by displacing the pest colony. Communication with your client about the process is essential. Review your action plan with timelines for follow up and get the “buy in” up front or find a different strategy.
• Some populations of insects avoid baits with glucose, and possibly even fructose, as an attractant. Considering that insects can detect what type of sugar is used, you must be aware of any potential reason the target pest is not interested. Sample multiple types of baits on day one to find out which is most attractive and verify that the bait is accepted.
• Resistance — unfortunately, sometimes the active ingredient fails to deliver mortality. Bait rotation is a must if we value the benefits of one of the most significant treatment strategies in the industry. There are multiple factors involved in the bait choice: use different attractants, use active ingredients with different modes of action, use newer baits with multiple actives or multiple attractants at least quarterly.
• Bait can become contaminated by external sources. Insects and rodents have a keen sense of smell and taste; consider the consequences of even slight chances of contamination. Rats can taste chemical contaminants in their food in parts per billion. (Source: Rodent Control: A Practical Guide for Pest Management Professionals, Robert Corrigan, published by GIE Media, 2001.)
• Don’t use contact residuals or repellents in the vicinity of the bait. Store baits away from other products, both in the warehouse and in the service vehicle. Using other products could mask the scent of the attractant, leave an unpalatable taste, change the feeding behavior or even kill the target pests before they have a chance to transfer the active ingredient back to the colony.

Educate the customer about using cleaning agents after the treatment or “self treating” with foggers and over-the-counter pesticides. Doing so could disrupt the treatment plan as stated previously. Control the environment of the bait. Excessive heat can cause separation or degradation of the active ingredient, and moisture can wreak havoc on some bait, especially granular formulations. Use caution during storage and with weather conditions after treatment. Store baits in plastic containers with tight lids to avoid odor contamination and put gel formulations in small coolers with freezer packs during the summer heat. Always keep material in original packaging, using the storage containers as outer protection.

And, don’t forget about your hands; sanitizers, lotions, cigarette smoke and gas from the pump handle will definitely ruin your chances of success.
 

Final Thoughts.

Using bait as a primary control method can be very effective — optimizing usage by following best practices is even more effective. The keys to success depend on solving the issues and carefully utilizing the options we have in bait formulations.

Larry Motes is director of operations for Gregory Pest Solutions, Greenville, S.C. He has served in the pest management industry for more than 28 years and holds a bachelor of science degree in entomology from the University of Georgia.

Copesan is an alliance of pest management companies with locations throughout North America. To learn more, visit www.copesan.com.