In my opinion, unless you live in the deep south where there is only one season, spring is the most spectacular season of the year in our area. It is the season when the sleeping giant, nature, awakens, and many animals we label as pests renew their cycle of life and the demands for our services increase exponentially.
It is important to recognize that most of the pest problems confronting our customers arise from the exterior of the structure and the earlier we attack the perimeter the easier it is to keep the problems in check. As pest populations increase it becomes more difficult to manage them at acceptable levels because they expand their niches, and their sheer numbers can become an obstacle.
Hodge (1911) gives one of the most dramatic examples of an insect’s (house fly’s) capacity to populate. Based on the capacity of a single fly to lay 120-150 eggs per batch and a minimum of six batches at 3-4 day intervals he concludes: “A pair of flies beginning operations in April may be progenitors, if all were to live, of 191,010,000,000,000,000,000 (191 quintillion 10 quadrillion) flies in August. Allowing one-eighth of a cubic inch per fly, this number would cover the earth forty-seven feet deep.”
While we are unlikely to encounter these extreme pest populations, insect populations do have the ability to explode. Because insects are greatly affected by environmental conditions, they have a relatively short period of time to exploit the resources the environment and season have to offer. Once these change and/or are depleted, pests seek out more consistent human environments readily available to them. The keys to offsetting pest problems are to act early, alter their environment, deprive them of the human environment, and attack the perimeter before they have a chance to multiply and enter structures.
It is much easier to manage insect populations as they begin to expand in the spring, as opposed to waiting until their numbers reach the carrying capacity of the environment. You and your customers can have a direct impact on the carrying capacity of the environment.
Foundation landscape plantings are probably the greatest attractant for pest insects because they typically offer everything the expanding population needs:
You can’t expect your customers to completely eliminate landscaping from the perimeter of their structures. However, you can advise them on techniques to appropriately manage this environment, thereby minimizing pest problems by stressing the population. For instance, thinning the mulch layer, reducing water applications, allowing air to circulate under hardscape items, and replacing landscape timbers and other wood with synthetic materials.
The selection of plant material around the perimeter can be a factor in reducing pest pressure around the perimeter. Using plants that are insect and disease-resistant can have a positive impact. By minimizing aphids, scale, whiteflies, and other honeydew producing insects and the associated powdery mildew, the perimeter will be much less attractive to perimeter pests. In cases where these attractive conditions exist washing the plants periodically throughout the growing season will remove much of the sugary secretions produced by these insects.
Ants are one of the best examples of insects that take full advantage of what nature, and the human habitat described above, have to offer. They have a distinct advantage over many other groups of insects in that they are social insects that work together for the betterment of the whole. In part, this works to their advantage, but there are elements of their behavior that can also work against them.
One of the keys to the success of ants is their ability to find and exploit resources using pheromones. Once a food and/or water source is located the line forms and may extend hundreds of feet ferrying supplies back to the colony. The downside for the ants is that liquid and granular baits, as well as non-repellent insecticides, can also be transported unknowingly back to the nest, resulting in colony destruction.
Insect habits and behavior are significantly affected by the time of year and the availability of nutrients. You must be aware of these changes and how they affect the products you use and the the method of application you apply. For instance, liquid and granular baits can be very effective against foraging insects and surface feeders. Non-repellent insecticides may be equally effective against these types of insects, in addition to those that spend most of their time under protective layers. Products with a repellency factor can be very effective on the perimeter in keeping pests away from the foundation.
The product formulation is another important factor to consider. Granules applied to the soil can provide long-term control, but in the absence of water they are relatively ineffective. Liquid applications are less durable but provide immediate results, particularly on direct contact.
All too often our initial inclination is to go after most pests from inside the structure. Undoubtedly this provides some degree of success, e.g., it kills some pests, but rarely does it solve the problem. Attacking the perimeter provides a solution to what you and your customer want - a longer-term solution to their pest problem.
Adapted from an article originally published in PCT May 2006