Providing Better Cockroach Control in Multifamily Housing

Editor’s Note: This story first appeared in PCT Canada’s 2021 Show Edition.

Controlling German cockroach populations in multifamily housing continues to be one of the biggest challenges for pest management professionals. It doesn’t have to be this way.

The industry has the knowledge and tools to control these pests. “We can, no questions asked, eliminate German cockroach infestations from multifamily housing and with no resident cooperation required,” said Dini Miller, an urban entomologist at Virginia Tech University.

A few years ago, Miller conducted a field study that found German cockroaches can be eliminated from highly-infested multifamily housing using an assessment-based approach, an appropriate amount of gel bait as the only means of control and without requiring residents to empty cupboards, remove clutter or clean before treatment.

And in 15 years of conducting field research, she’s observed numerous missteps that PMPs make when selling and delivering this service to multifamily housing. As a result, tenants live in units that are regularly treated but continue to be plagued with cockroach problems.

This begs the question: “Are you in the pesticide application business, or are you in the pest control business?” asked Miller at a PCT Virtual Conference on cockroach control in May 2021.

At the seminar, Miller shared 10 common mistakes PMPs make when it comes to German cockroaches and how to avoid them.

Mistake No. 1

PMPs and their salespeople often bid on multi-unit housing jobs without inspecting the units first. Instead, they rely on the building’s square footage to determine pricing. Miller called this approach “ridiculous.”

First, cockroaches inhabit a cubic space, not just an area determined by its length and width. The pests also travel upward, congregating on walls and ceilings. “We need to take cubic footage into account if we’re going to think about how long the technician is going to need to spend in each unit,” said Miller.

Nor does calculating square (or cubic) footage determine the level of infestation, which in turn determines how much time and product are required to successfully eliminate the cockroach problem. Before bidding jobs, inspect units so you know what you’re getting involved in.

Mistake No. 2

Underselling the job so technicians have no time for pest control. When jobs are underbid, technicians may not have enough time to address the cockroach problem in each unit and still make production. Not only is this stressful for technicians, but it is demoralizing. Miller asked: How do you attract new technicians if they feel their work is pointless?

She urged PMPs to move away from charging the same amount for each unit (typically about $5 a door) and to be transparent with property managers by sharing how many minutes your bid price gives technicians in each apartment. It may sound good that a technician will spend two hours servicing 30 units for $150, but that’s only four minutes spent in each unit, and this may come as a surprise to the client, Miller pointed out. “What are our customers getting for their money? They’re certainly not getting pest control,” said Miller. PMPs should also address accountability, like whether salespeople should earn commission if they underbid units.

Mistake No. 3:

Not informing clients about what you do or the products you use. In Miller’s experience, PMPs typically don’t provide property managers with a list of products used on site; they don’t specify what their treatment or IPM practices entail; and they often apply the oldest and least expensive spray formulations without informing management of other product options.

While PMPs may report the total amount of time spent on site and the quantity of product used for all units treated, this data usually is not available on a per-unit basis. And rarely are individual units assessed for cockroach population size. “I really think that’s important, especially for managers to know,” she said.

Mistake No. 4

Not doing intensive treatment during winter months. German cockroach populations will triple or quadruple in size during summer months, then drop off significantly in winter. It’s easier and more effective to eradicate a smaller population.

“It makes no sense for us to start our treatments during the summer. We can evaluate during the summer; then we need to hit them hard during the winter,” explained Miller.

She suggested conducting an assessment in each unit in August using three large glue traps placed above the sink, below the sink and behind the toilet. In September, use that data to develop a treatment plan, and from October through December, treat units with the largest infestations. Then, from January to March, focus on units with medium-size infestations, and target units with small infestations April through June.

“You will be so surprised at the results if you do what is needed to get rid of these roaches; they will not have the summer explosion,” said Miller.

Mistake No. 5

Not focusing on insecticide resistance. “If you don’t know a lot about resistance, learn about it,” urged Miller. German cockroaches are particularly resistant to pyrethroid insecticide sprays, “because they’ve been exposed to these same formulations over and over,” she said.

According to studies conducted in multifamily housing, three types of resistance exist in German cockroach populations. Some have developed “extra thick skin,” which makes it harder to get pesticide inside the cockroaches. Called reduced cuticular penetration, this affects the residual activity of products. “If those products have dried for 40 minutes and these cockroaches with thick skins go walking across it, they will not pick up a lethal dose,” explained Miller.

Cockroaches also may have enhanced mixed function oxidase activity. “These are cockroaches that just so happen to have enzymes inside of their body that break down toxicants as soon as they get in there,” said Miller. They might get knocked down by insecticide but pop back up a few hours later, dazed but alive.

Other cockroaches have a mutation on their nerve sites where pyrethroid insecticides are supposed to lock in and work but do not. As such, the industry must employ “novel products” like baits and rotate chemicals every three months. PMPs need to educate property managers about resistance, why certain products are used and when, and why the expected spray may not be applied.

Mistake No. 6

Mixing sprays with bait. “You are wasting bait if you’re using spray at the same time,” said Miller. Flushing agents, for instance, repel cockroaches so they’re busy running and not stopping to eat. Bait can get contaminated by spray, making it less appetizing. And sprays may knock down some cockroaches initially, but due to enhanced mixed function oxidase activity, the pests may later revive but aren’t hungry because they’re feeling somewhat hungover.

Even cleaning and emptying cabinets prior to treatment will disturb the cockroaches, causing them to scatter instead of feed on bait. “We want them to be relaxed and hungry,” explained Miller.

Mistake No. 7

Guessing how much bait to apply. Several studies have found that because technicians are pressed for time in multifamily units, the amount of bait they applied in cockroach-infested apartments was far less than required. “This can be 120 times less than what is needed for effective treatment,” pointed out Miller.

Mistake No. 8

Not having the resident home during treatment. Miller has learned firsthand that residents of multifamily housing don’t believe PMPs are the experts. Rather, they believe the miracle is in the spray, and the reason they still have cockroaches is because PMPs don’t spray enough. In fact, that’s why they have so much over-the-counter spray in their home. “They think they can do a better job than you because they can spray every day and you’re there once every three months,” said Miller.

Also, ask them not to spray for three days after you leave. They won’t agree to stop spraying forever, but if you give them a small time frame, they’ll likely acquiesce. In addition, let residents know that when you return in three months, you’d like their opinion on how the treatment went and where they continued to see roaches. “Most people are so grateful for that. Nobody’s asked them their opinion,” said Miller.

Mistake No. 9

Blaming residents for pest control failure. For decades, the industry has blamed residents for pest control failures, said Miller. This excuse is not valid, as she’s proven German cockroach infestations can be eliminated without residents improving sanitation or reducing clutter.

“Resident clean-up is not necessary for us to succeed,” said Miller, citing her field work in multifamily housing complexes. Not only does the industry have data now to prove an assessment, bait-only control approach works, but it has attractive bait products that can outcompete other food sources and that the roaches find “delicious,” she said.

“We can eliminate the cockroaches. We can control them regardless of the residents,” Miller assured.

Mistake No. 10

Not sharing data with managers. The only way to show your value as a professional service provider is to share data with property managers, even if they don’t ask for it.

Data is more than reporting trap counts. Therefore, email them photos of cockroaches eating bait; dead cockroaches; roaches caught in glue traps, especially as these numbers decline. “I’m a big believer that we need to pass on documentation of our success to the management,” said Miller.

Because assessments rarely are conducted, property managers don’t understand how extensive the cockroach problems are. “Managers have no idea that their units are so infested because they never look, and this is why I insist that you send them pictures,” said Miller.

As well, she suggested PMPs state in their bid contracts that they will provide documentation indicating fewer cockroaches after treatment. “Customers need to know what you’re doing and what they’re getting for their money,” she explained. Show them the problem and how you’re solving it.