ANTswers From a Leading Entomologist

PCT: During your career, you’ve been able to observe ant control from a national perspective. What are some aspects of ant control that are the same regardless of location and what are some important regional differences?

Stoy Hedges: Although ant species, as well as construction types and climates, vary throughout the country, the factors that attract ants to buildings remain pretty much the same. The type and extent of landscaping around structures provides shelter and food resources for ants close to buildings and even in dry regions, moisture is plentiful due to irrigation.

The species of ants that become pests are those that thrive in the conditions we provide right next to our foundations. We like trees in yards that give carpenter ants sites for parent colonies from which they establish satellite colonies in the home. We plant fruit trees, shrubs and flowers that are prone to aphids and other insects that pest ants use as food. We install mulch in landscape beds, plant thick ground covers, store things in piles outside our homes and sheds, maintain flower pots and allow leaf litter to accumulate — all of which serve as nesting sites for many types of ants. All of these factors are consistent across the U.S. and different species of ants take advantage of them.

As far as regional differences, it comes back to climate and the types of species present. A pest management professional in the New England area has maybe three to four different ant species he’ll encounter on a regular basis. A PMP in South Florida has to be prepared to encounter up to 15 different species, depending on the neighborhood his route takes him. In California, the ant they spend the most time battling is the Argentine ant. In Tennessee, the odorous house ant is the most common in structures. In Washington and Oregon, two species of carpenter ants generate the most calls and service issues.

SH: If you spend enough years in this business, you will find that older buildings and homes are more prone to pest infestations and invasions. Newer homes experience ant problems too, but older properties have mature landscaping and maintenance issues that create the conditions for more ants, both in species and number of colonies to thrive.

New homes will not have moisture issues seen in older homes where roofs may have small leaks, gutters haven’t been adjusted for best removal of rainfall, and the trees are typically smaller and not creating as much shade as is found with older homes. The plants in landscaping are smaller and less lush, and leaf litter is usually not much of an issue because trees have yet to mature, providing greater leaf volume to accumulate.

On the flip side, new home construction is highly disruptive to the immediate environment and some ant species thrive in disrupted environments, in particular, the imported fire ant and crazy ants.

PCT: Can you give us an example of how knowing an ant’s biology and behavior (including its weaknesses) can be used against it?

SH: The key to ultimate success in ant control is finding the colony and killing the queen(s). You can treat and kill thousands of workers but if the colony is still viable, the threat of infestation inside will remain. The most basic biology aspect for a pest professional to understand is the nesting habits of each ant species found in their area. Once you know the nesting preferences and have identified the offending species, you then look for sites in and around the structure where that species’ preferred nesting conditions exist. This is easier to do with some ants than others.

Carpenter ants (most species) and acrobat ants prefer to nest in moist, dead wood.

Pavement ants and fire ants are soil nesters. The most difficult ants, however, are opportunistic in nest site selection. Argentine ants, crazy ants and odorous house ants, for example, will build shallow nests in soil but will locate sub-colony nests in a variety of sites from mulch and leaf litter to gravel, piles of items, insulation, potted plants, meter boxes and irrigation heads.

PCT: What are some important changes made from the 2^nd edition of the PCT Field Guide for the Management of Structure-Infesting Ants to the 3^rd edition, and why is it important for PMPs to update this essential pest control resource? What type of feedback have you received from those who purchased this book?

SH: With each edition, new ant species are added and information on all ants is updated based on new research as well as my own experiences. I tried to make the field guide as applicable as possible for solving real-world ant issues, especially as I’ve learned more.

I’ve gotten nothing but great feedback from those who have used the ant field guide. It’s always great to hear a person tell me they carry their ant field guide everywhere in their truck and the copy is used so often that it’s worn out. That means I’ve met my goal of creating a tool that helps pest professionals do their jobs better.

PCT: The ant field guide is one of several field guides you’ve published through your PCT partnership. Others include the PCT Field Guide for the Management of Structure-Infesting Flies; PCT Field Guide for the Management of Urban Spiders, 2^nd Ed.; PCT Field Guide for the Management of Urban Spiders, 2^nd Ed.; and the PCT Field Guide for the Management of Structure-Infesting Beetles, Vol I. and Vol. II. How can these books be integrated into a training program and also used in the field?

SH: Any reference material can be incorporated into training. The easiest way is when you are out in the field with a new pest professional and showing them how to identify ants and use the field guide to solve the problem at hand. No one person can know everything, so the best approach to training is teaching people how to effectively use their resources.

If a manager or trainer takes the time, he or she can create problem-solving exercises with various pests. They can have their trainees use the field guides and magnifiers to identify specimens, and then give recommendations for solving various scenarios involving each particular pest. To do this, collect specimens and have them available in the class; be prepared with scenarios involving each pest included. Have a copy of the appropriate field guide available for each person to consult as they try to come up with the recommendations to solve the pest problem. The Case Histories chapters in some of the PCT field guides can help trainers understand how they might turn their own real-world experiences into scenarios that can be used in this type of training.