By: Kim Kelley-Tunis, B.C.E.
When creating or reviewing a pest prevention program, we often develop strategies based on the pest’s microenvironment. By that I mean our attention is squarely focused on the areas in which we are observing the pests or their damage. We tend to operate on the assumption that corrections or changes in these areas will greatly impact the success of our program. As a result, we lose focus on other aspects of the environment that could alter the success of our pest management programs, including the presence of predators, temperature and climate, and other disturbances that modify the otherwise normal behavioral patterns of the pests we are trying to prevent or manage.
First, we need to clarify and understand the difference between the terms “microenvironment” and “macroenvironment.” According to the Oxford English Dictionary, the microenvironment is the immediate small-scale environment of an organism, especially as a distinct part of a larger environment. In terms of our prevention strategies, that delineation includes any structure that a pest may try to enter, whether residential or commercial. This microenvironment is sufficient to provide all the resources needed for a pest to survive and in many cases thrive, including food, water and shelter. The macroenvironment, on the other hand, is the larger environment in which we live. It includes the neighborhood, city or state the structures are in. The fact may seem odd, but changes within the broader macroenvironment also can have a significant impact on the success of your pest prevention program.
Last year, for example, with the introduction of the coronavirus, we had the opportunity to see just how changes to the macroenvironment can significantly impact a pest’s behavior. Changes in how we lived our lives forced insects and animals across the globe to change their behaviors. As more people began to stay home and away from their normal places of business, we began to see a shift in the pest population. Due to a lack of predators and an increase in available resources, sightings of nuisance wildlife and insect pests in, and around homes and neighborhoods also increased in response. The pests that remained in deserted urban areas were forced to scavenge for whatever resources they could find, often resorting to cannibalism to survive.
Buildings and shops within shared structures that were forced to close with little preparation reopened to find once pest-free zones inundated with insects and rodents searching for resources. While it is unlikely that we could have predicted the behavioral changes resulting from the coronavirus shutdowns, we can now recognize the potential for these environmental changes and put strategies in place to help increase the success of our pest prevention programs.
One of the most common environmental changes that impacts the success of a pest prevention program is construction. Yes, construction within a specific structure will alter pest behavior, but so will construction within a building, neighborhood or city. The clearing of land, removing vegetation and disturbing soil can cause mass numbers of pests to move into otherwise unoccupied areas. Nuisance wildlife and pests that relied on those readily available resources are now forced to search for food and shelter needed to survive. In urban areas, construction of large buildings drives pests to utilize common utility penetrations and also to search for resources lost during the construction process.
EFFECT OF WEATHER
In the last several years, changes in weather patterns have had an impact on both the pests that our customers are seeing as well as their behavior patterns. This slow transition is most visible in the change to the plant hardiness zones as described by the U.S. Department of Agriculture. Often used by gardeners, the USDA map of plant hardiness zones is commonly used to help gardeners identify which plants will survive within a particular geographic area.
This document also can be a helpful tool for pest professionals. As described, there has been a shift of at least one hardiness zone, especially in the northern U.S., from a cooler to warmer zone during the 1990 to 2006 reporting timeframe. These changes in weather patterns not only impact the types of plants growing within these zones but also can have a significant impact on the insect fauna that rely on those plants for survival. The temperature changes also can cause these pests to alter what we have seen as “normal” behavior.
For example, pests that normally do not emerge from their winter slumber until the warmer spring months may now begin to emerge during the late winter or early spring. We also may begin to see more pests often seen in the southern states moving north, following the movement of their herbaceous plant-based food sources.
Lastly, the introduction of new or invasive pests also poses a problem that we can work to lessen or eliminate through our pest prevention programs. When brought into an area without predators but with an abundance of food, newly introduced pests have the ability to grow their populations and force native species to seek resources and shelter in other areas. The most recent introductions of the spotted lanternfly and the Asian giant hornet, for instance, have shown how having an action plan in place can help to reduce the pests’ spread and protect the existing environment.
While it’s impossible to plan for every pest that may enter structures we are being asked to protect, we can use our knowledge of the greater macroenvironment to identify strategies that can help mitigate damages through a predictive pest prevention program.
Kim Kelley-Tunis is an associate certified entomologist, board certified entomologist and is PCQI certified. She is the Technical Manager for Terminix Commercial, a sister brand of Copesan.
This Tech Talk article was originally published in the April 2021 edition of PCT magazine.