[Book Excerpt] Managing Cockroaches in Food Service Facilities

Editor’s Note: The following article originally appeared in the September/October 2014 issue of PCT Canada, sponsored by Univar.

When it comes to commercial kitchens and food-handling facilities, cockroaches are the most prolific, adaptable and determined pest. They reproduce rapidly, eat almost any organic substance, and thrive in hard-to-reach cracks and crevices that offer warmth and humidity.

German cockroaches are the most common species found in food-handling establishments. Others include the American cockroach and brownbanded cockroach.
 

Inspection Pointers.

German cockroaches generally harbor in the cracks and crevices of warm, wet locations. Although they prefer fermented food spills, they will consume just about anything, ranging from food crumbs, grease and spilled beer to soiled clothing and dried glue.

Sanitation is essential to control these pests. During your inspection, identify signs of cockroach activity and harborage areas. Because your control program likely will involve baits, consider the many alternative food sources available. Most important, find their sources of water, such as standing puddles and condensation on pipes and appliances. Frozen items placed on metal countertops cause condensation on the undersides of these surfaces; combined with the gaps in countertop joints, this makes for an ideal German cockroach habitat.

Commercial kitchen equipment, with its multitude of cracks, seams, folds and holes, are cockroach havens. Carefully inspect prep counters, ovens, dishwashers, beer and soda fountains, and mixers. Evaluate the rubber door seals of coolers and refrigerators that can crack and peel over time, providing harborage. Another problem area: stainless steel splashboards that have separated from walls. Check that escutcheon plates around plumbing pipes are secure and that no gaps exist around electrical conduits that run between cabinets and walls or floors.

Educate the client on the importance of maintaining equipment and site cleanliness; document the repairs and maintenance needed to help control cockroach populations.

Use monitoring traps high and low in as many areas as possible. These monitors will help you identify the extent and relative direction of German cockroach harborage areas. For example, if you are finding nymphs on one side of a trap, you likely have a harborage area within a few inches of that side. If you find adults on one side, the harborage area is on that side but potentially a little further away. If you’re finding all stages of cockroaches on all sides, you’re probably dealing with multiple harborage areas.

Document your findings, actions and recommendations, and create a detailed site map. Include your schedule for applying bait treatments. This is especially helpful in large kitchens with many treatment zones. The schedule will help a technician who services the account monthly ensure that quarterly baiting is accomplished, without having to spend excessive time baiting all areas during one visit.
 

Treatment Options.

In severe infestations, use mechanical means to reduce population numbers, such as using a HEPA vacuum. Flush out hiding pests by applying a liquid flushing agent/contact aerosol to harborage areas; suck up emerging cockroaches with the vacuum.

Heat treatments can provide quick knockdown of large populations. Be sure to protect heat-sensitive items. Only trained, experienced individuals should attempt heat treatments.

These approaches don’t provide long-term or residual control; the use of cockroach baits and/or liquid residual sprays is required.
 

Baits — Gel and containerized baits rely on various active ingredients. For long-term control, choose one that is effective and palatable. Also rotate the use of active ingredients, not merely brands that may contain the same active ingredient, to prevent the pests from becoming insecticide resistant.

Generally baits are applied in small doses near harborage areas, not on exposed surfaces (always read the label before application). Be careful not to contaminate bait by applying it near repellent dusts or liquid residuals. Place sticky traps near baiting areas to determine if cockroaches are visiting the area enough to justify placing the bait there. Inform your client and his or her cleaning staff what bait looks like so it is not accidentally removed.
 

Dusts — Dusts can be applied to cracks and crevices where cockroaches hide; applied correctly, they generally last for months. Dusts take longer to work than liquid residuals because they are desiccants and require grooming to be effective, but they offer a long-term control solution.

Dusts containing boric acid or diatomaceous earth have minimal toxicity and are non-repellent, but lose effectiveness if they get wet. Insecticide dusts generally are repellent and have stricter labels; some remain effective after being exposed to water. Read product labels and consult your distributor representative to determine the best dust for your account.

Proper application of dust is essential. Ensure your training is up to date; practice application techniques.
 

Liquid Residuals — Several factors must be considered before selecting a liquid residual spray. First, is it labeled for use in commercial food-handling establishments? Carefully review the label: Does the client need to prepare the site (e.g., cover food-handling surfaces) before application? Is the product for crack and crevice application only? Are any post-treatment steps (e.g., wiping down countertops) required?

Then, select a product that will stand up to the environment. For example, accounts with a lot of greasy buildup need a chemical that will remain effective; spotless kitchens will have more options.

Choose between a repellent and non-repellent product. A repellent product may work best at an account with very little cockroach activity and little bait use. A non-repellent is best suited for kitchens where baits are used more frequently.

Finally, insecticide products that contain an Insect Growth Regulator (IGR) offer long-term control. While baits, dusts and liquid sprays kill great numbers of cockroaches, the IGR prevents survivors from breeding.

This article was adapted from the PCT Guide to Commercial Pest Management, Chapter 17: Pest Management in Food Service Facilities by John Cooksey of McCall Service, and Victoria Fickle, Hawaii State Department of Agriculture, Pesticide Branch.