By Joe Barile
Technical Services Support, Environmental Science, Bayer CropScience LP
Ants live in colonies where individual members of the colony function for the purposes of maintaining the nest and reproducing to form additional colonies. Ant behavior is truly social, where the needs of individual colony members are not important. For pest management professionals (PMPs), this means that efforts must focus on colony elimination.
Invading from outside, worker ants (“foragers”) are what most customers see inside their homes. Yet, it is important to know that a large number of foraging workers might only represent a very small portion of the entire ant colony’s population. Because of the colony’s social behavior, both the PMP and homeowner must understand that to eliminate an ant colony, control efforts must target the queen(s) and brood (immature stages) of the colony. Failure to eliminate the queen and brood will result in only temporary relief, as the reproductive potential of the colony will provide replacement ants that will re-invade the structure.
A comprehensive colony elimination program must include:
• Identification — Know the species, size of colonies, nesting sites and behaviors.
• Inspection — Examine the inside and outside of the structure to identify resource sites; access and entry into the structure; and conditions conducive to ant activity.
• Exclusion — This includes such actions as trimming shrubs and trees off the building surface; sealing utility penetrations and cracks that allow ants entry; advising on ill-fitting door and window seals.
• Environmental management — Remove or alter conditions (accumulated leaf litter, firewood stored indoors or against foundations, etc.) that support activity and may provide nesting sites. Repair leaks that provide ants with water, an essential resource.
• Landscape management — Ants may be attracted to certain ornamental plants that produce attractive nectars and/or support plant-feeding insects (scale, aphids, mealybugs, etc.) that produce honeydew.
• Sanitation — Eliminate attractive food sources in and around garbage areas, pet feeding areas and kitchens.
• Insecticides — Use specific formulations, taking advantage of their performance features. Always read and follow all label directions.
• Use dusts to treat enclosed voids or entry sites, eliminating potential harborages or foraging paths.
• Use baits outdoors to “intercept” ants before they travel inside where customers may observe them. Bait as close as possible to nest sites and outdoor entry sites. Remember to place a sufficient amount of bait to ensure cross-feeding and exposure back to the queen(s) and brood in the nest sites. If indoor baiting is considered, educate customers about activity expected to be observed based on the bait’s attraction.
• Apply sprays to specific foraging trails and entry sites around the structure’s perimeter. Some spray products allow the treatment of outdoor ornamentals to control honeydew-producing insects. Important spray sites in perimeter treatments include the sill/foundation interface, usually under the first row of siding on the building.
Comprehensive ant management combines integrated non-chemical control efforts with multiple formulations of insecticides to eliminate ant colonies, protect structures and satisfy customers.