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Establishing PEST CONTROL Thresholds - When is Enough Enough?

Written by  RON HARRISON, PH.D.

Hand Roach

In a survey released by Orkin and the building Owners and Managers Association (BOMA), 50 percent of office tenants reported that recurring pest issues would prompt them to look for new office space. Almost 90 percent of tenants reported seeing a pest in the office in the past 12 months.

That means tenants have a low tolerance for pest presence, yet almost one in 10 recall a pest sighting—and half said they would report it after just one incident. Your tenants’ tolerance threshold is one to consider, but there’s also the threshold for when it’s time to take programmatic action. This means that BSCs involved with pest control will need to determine what level of pest activity warrants corrective measures—and this needs to happen well before the problem starts.

Aiming for zero pest sightings—even with a strong pest control program in place—is virtually unattainable given the pest pressures facing most facilities, including office buildings. From geographic location and building density to the age of infrastructure and property amenities, numerous variables impact the pest-threat level at a property. Given this, it’s important to work with tenants to set these thresholds, keeping realistic expectations in mind and accounting for all of the variables that can affect pest presence at each of the facilities you clean.

Incorporating pest thresholds into your ongoing Integrated Pest Management (IPM) plan ensures that you know what activity to react to, when to react, and how. An IPM program is an environmentally conscious approach to pest control that can be implemented immediately, focusing on proactive sanitation, habitat modification, and facility maintenance. Pest thresholds also help you communicate to tenants about how you plan to address pest issues once they’re brought to your attention and why you’re taking a particular corrective action.

When it comes to setting reasonable pest thresholds, here are some questions to consider:

How does your building’s environment impact your expectations?
“Location, location, location” is the old real estate adage. And it’s definitely one of the core considerations for setting pest control thresholds. Pest populations vary from region to region across the country, requiring different approaches depending on the particular species that are active in your location.

Beyond geography, urban environments pose different threats than suburban or rural locations. Other aspects of the exterior setting have an impact as well: is the surrounding area forested, close to a retention pond, or extensively landscaped? Harborage as well as food and water supply can attract pests to the exterior of the building, increasing the pest pressure and likelihood that pests could become a problem inside the building.

Also, different seasons of the year can have a significant impact on pest pressure. In fact, just because you may not be seeing pests at a certain time of year doesn’t mean that the issue has been resolved, so it’s important to factor the seasonal weather changes into both your expectations and your action thresholds.

How do the characteristics of the facility affect thresholds?
Regardless of its age, cracks and crevices can compromise a building’s structural integrity and open it up to more pest pressures. This is one of the reasons why LEED requires buildings to be tightly sealed. Mixed-use buildings that include foodservice have heightened pest pressures, and those that compile retail and residential areas with traditional office spaces also present unique challenges.

Building construction and materials can also make a difference, not to mention building density. The number of people traveling in and out of a building on any given day can seriously impact the levels of pest activity.

If you’re servicing an older property and want to significantly reduce pest presence, expect recommendations for exclusion measures that will require additional investment in building maintenance. Mixed-use properties will need to take a more stringent approach to food safety and sanitation to reduce pest pressure, which may require employee training and certification. For high-density buildings, your provider may recommend control measures around entrances.

Are your expectations and timeline reasonable?
If you have a newer building with no current pest issues, it’s reasonable to work with your pest management provider to establish a zero-pest threshold for most pests. This approach will require close communication with your pest control partner, a strong IPM program, and an ongoing cycle of assessing the building environment, implementing corrective measures, and monitoring their effectiveness, adjusting accordingly.

But if you are currently battling pests—whether they are cockroaches, bed bugs, ants, flies or rodents—going from a threshold of 1,000 to zero takes time. Work with your pest management provider to create a timeline for steady and reasonable improvement and consistently evaluate progress.

Which pests concern you—and your tenants—the most?
A single ant crawling across a lobby may not necessarily be a sign of a major pest problem. But an ongoing ant problem in an office suite or in common areas is something to be addressed.While some thresholds are imposed by government regulations or building certifications that require chemical usage reduction, many pests are afforded different thresholds due to cultural responses. Many people will tolerate—and probably not even notice—that rogue ant in your lobby. However, according to research, rodents are the number-one pest that tenants don’t want to see, so fewer sightings will trigger a response. Cockroaches follow in the least-tolerated category, so thresholds around these two pests may be set lower than other less threatening or distressing pests in the office environment. Every property is different. Talk with your professional about the pests you want on your zero-tolerance list.

How can you keep track of pest pressures?
There are several methods your pest management professional can use to help manage your pest issues, while also measuring against your thresholds. General inspections during a service visit may result in identification of pest activity. Mechanical and non-mechanical monitors, such as fly lights, insect traps, and sticky glue boards are often used to record pest activity levels passively between visits. In addition, your employees and tenants can be part of tracking pest activity by sharing any sightings with property management.

Make sure you and your pest provider keep records of all pest issues. Over time, you can determine whether progress is being made against your thresholds timeline and your efforts to reduce specific pest presence. Charting activity will also help you prepare your building for seasonal pest pressures in advance. Remember, a pest provider should have your thresholds and goals clearly written into your scope of service.

Pests are ever present season to season, but knowing what to expect and when to take action will help you maintain a strong proactive IPM program—and prevent pest-adverse tenants from crossing their personal pest tolerance thresholds.

Ron Harrison, Entomologist, Ph.D., is Director of Technical Services for Orkin. He is an acknowledged leader in the field of pest management with more than 30 years of experience. Contact Dr. Harrison at This email address is being protected from spambots. You need JavaScript enabled to view it. or visit www.orkincommercial.com for more information.


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