Down the Drain

The key to controlling nuisance flies in commercial accounts requires targeting one of their most common breeding sites — dirty floor drains.

While cockroach control continues to be an important profit center for PCOs, the growing effectiveness of baits has some industry observers wondering about the future growth potential of this market. Fortunately, in the wake of the industry’s recent success with cockroaches, a new problem has developed in many commercial accounts — nuisance flies.

Could these two developments be related? It’s not out of the question. In fact, based on my observations at Anderson Environmental Systems, Elmhurst, Ill., there seems to be a correlation between a recent reduction in crawling insect-related service calls and an increase in nuisance flies in many of our commercial accounts.

Before baits began their impressive record of success, most PCOs used emulsifiable concentrates to control cockroaches and other crawling pests. Typical treatments involved spraying insecticide into cracks and crevices, along baseboards, and in and around drains, thereby suppressing flying insect populations.

With the widespread use of baits, however, drains are no longer the focal point of many treatments, prompting an increase in service calls for nuisance flies (i.e., fruit flies, phorid flies, fungus gnats). As a result, there’s been a surge in flying insect control problems in commercial and industrial accounts.

What can you do about it? I recommend a three-step IPM program involving: (1) the use of food attractant traps to monitor and trap adult flying insects; (2) removal of organic debris in drains that serve as a breeding ground for nuisance flies; and (3) the installation of ultraviolet light traps to suppress the adult population.

THE FIRST STEP. Let’s start at the beginning. As you probably know, most problems associated with nuisance flies stem from these pests gaining a foothold in buildings because of poor sanitation. Standing water, combined with organic debris in drains or in cracks and crevices, creates an attractive breeding ground for these pests.

Therefore, it’s essential to conduct a thorough inspection prior to any treatment. Identify conditions where flies can breed (i.e., dirty drains, rotting fruit) and point them out to the customer for correction. List all drains in the general area where flies have been seen and make sure you locate mop sinks, traps and other moisture sources behind or under coolers.

The Natural Catch Plus Fruit Fly Trap is a useful non-chemical tool designed to monitor fly activity in commercial accounts, while helping to suppress adult populations. Nuisance flies are drawn to food attractants in the trap and perish in the liquid food attractant.

Next, clean up standing water and other potential breeding areas on floors and under equipment. Once you’ve done this, you can attack the drains. Combine a bacterial drain treatment to suppress breeding conditions with ultraviolet fly traps to filter out the adult fly population.

Remove the covers of floor drains and thoroughly clean out the organic matter from under the covers and the inside surfaces of the pipes. When treating commercial accounts at Anderson Environmental Systems, we recommend the application of DF5000 Ultra-Strength Drain Treatment into every drain. This product is specially formulated to attack decaying organic matter. It is a viscous gel that coats drain lines to attack decomposing organic masses. Pour it around the opening so it flows down the sides of the vertical drain pipe. It uses non-pathogenic bacteria (aerobic and anaerobic strains) that were selected for their ability to rapidly biodegrade decaying matter. This scum provides the egg-laying and larval development environment for all types of flies that thrive in these areas.

Purge the area by applying DF5000 for five consecutive days. Then treat the drains monthly to ensure that a build-up of organic material doesn’t recur. Remember, flies can reinfest an area within two or three months if treatment is discontinued. (Note: Do not use bleach or other common drain openers to remove organic debris from pipes. Bleach flows over and past the problem debris with-out significantly altering breeding sites. In addition, bleach will kill large numbers of beneficial bacteria and reduce the effectiveness of the DF5000 drain treatment.)

Be sure you treat every drain except the toilets and urinals. Floor drains, hand sinks, drinking fountains, mop sinks, bar sinks, soda fountain drains, beer tap drains, cooler drains and all others must be treated. If some are clean and others are dirty, flies will “flit” to the drains you missed to lay their eggs.

Each treatment of a floor drain should use at least 4 ounces of material. A good rule of thumb is to use about 1 ounce of product for each 1-inch pipe diameter. Make sure you pour the product all the way around the opening to coat the pipe walls. Pouring product down the center of the drain will not eliminate flies. Remove screens if they interfere with this process.

CONCLUSION. There’s no real secret to controlling nuisance flies — simply identify and eliminate all breeding sources and use a space treatment of a non-residual insecticide to knock down the adult population. Ultraviolet light traps — by themselves — won’t eliminate nuisance flies, but they will alert PCOs to the presence of these pests and provide some relief from adult flies.

The key to any control program, however, is eliminating the breeding sites, so pay particular attention to traps and floor drains in commercial accounts. If you don’t, thousands of dollars in potential profits could be “going down the drain.”

INNOVATIVE DRAIN TREATMENT ELIMINATES NUISANCE FLIES

Tony Wright, branch manager for Aable Pest Control, Waterloo, Iowa, says nuisance flies are a constant problem in commercial food facilities, but it’s a problem that is easily addressed.

“A lot of our accounts are food accounts — restaurants, bars, grocery stores and big food plants,” he said. “Any drain that isn’t under a cleaning program will sooner or later become a nuisance fly habitat. That’s because they lay their eggs in the organic matter that builds up around the side walls of a pipe. All of a sudden the account realizes they have a fly problem and they dump bleach down the drain. At that point it’s too late because bleach just bypasses the organic matter and goes down the pipe. So you’re not affecting the eggs at all.”

Wright uses DF5000 Ultra-Strength Drain Treatment as part of an integrated pest management program to control nuisance flies in commercial accounts. The program has proven particularly effective at a large food plant that was experiencing a serious phorid fly infestation recently. “We documented the phorid fly reduction by using 25 Gardner GT-200 Adhesive Light Traps in the production area,” he said. “We kept a fly log on how many insects were caught each day in each trap. I initially had as many as 250 flies in one trap and was down to zero after we applied DF5000.”

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