[Tech Talk] The Effects of Landscaping in Pest Management

Columns - Technically Speaking

February 26, 2013

Back in college, I struggled with choosing a career as a wildlife biologist or an entomologist in the pest management industry. I had no idea that 35 years later I’d be writing on landscaping and referring to a concept I learned in an introductory wildlife management course at North Carolina State University. That concept is this: “The more complex the harborage, the greater the carrying capacity.”

I also had no idea how universal this concept was for almost all arthropod species, including wildlife and insects. It should come as no surprise that many pest species we deal with inside structures are directly impacted by landscaping on our clients’ property. The more places for critters to hide, the more likely there will be more critters.

Landscaping can be broken down into five major components — trees, shrubs, low-lying vegetation, ground cover/mulch and “other” miscellaneous areas.

Trees. Determine the types of trees present, their age, condition and proximity to a structure. Keep in mind that most trees produce some type of seed, nut or fruit, all of which may serve as food for many pests. Some trees produce flowers that can attract other insects. Certain trees are more susceptible to attack by aphids and subsequently attract large populations of foraging ants that will feed upon the honeydew that they excrete. Older trees can be prone to holes or cavities, which can be attractive to vertebrate pests and many ant species. When trees are close to a structure, overhanging limbs often serve as natural bridges for all types of insect and vertebrate pests. Even if limbs aren’t touching a structure, they can still serve as a pathway onto power lines leading to structures.

Shrubs. Shrubs often create conditions that are attractive to pests. Like trees, many shrubs will attract insects due to seasonal flowering and large populations of ants that may be attracted by the presence of aphids. Densely planted shrubbery or shrubs with foliage extending to the ground can create an attractive home for rodents and other vertebrate pests.

Low-lying Vegetation. Areas of high grass, weeds, flowers, ivy or some other varieties of dense low-lying vegetation often serve as harborage and attract many pests. In our area of North Carolina, many of the peridomestic cockroach species thrive outside in areas where there are dense ivy beds and other vegetation of moderate height. During the summer, these cockroaches will often move directly into structures from these areas.

Ground Cover/Mulch.
There is a variety of mulch used around structures today. Some materials like shredded wooden pallets and hardwood bark mulch can create highly attractive conditions for pests. Some forms of ground cover/mulch, such as pine needles, may be moderately attractive to pest species. There are now synthetic pine needles and shredded tire mulches available that are less attractive to pests. A stone or gravel border is even better.

Customers seem to have a love affair with landscape timbers, old railroad cross ties and rocks. When I was a kid, the first place I would go to find a critter would be under a log or rock. We should keep in mind that many folks simply don’t consider that using old railroad cross ties around planter beds or structures would be attractive to pests.

Final Thoughts. Landscaping at a location directly affects the presence and movement patterns of pests, and directly influences food, harborage and the availability of moisture to arthropod life around the exterior of structures.

We always should inspect and evaluate the landscaping on our clients’ property. We should provide recommendations to prevent potential issues, including modifications in landscaping. By providing these evaluations and recommendations, we are delivering a value-added service to our clients, and reducing the potential for future pest-related concerns at their homes or facility.

McNeely is president of McNeely Pest Control, Winston Salem, N.C. A member of the Copesan Services Technical Committee, McNeely has served on the board of the North Carolina Pest Management Association, is a member of the Entomological Society of America and is a North Carolina Wildlife Damage Control Agent.

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