Keying in on certain commonly infested sites can go a long way to achieving successful cockroach control in these complex environments.

Commercial kitchens come in all sizes, from small prep kitchens found in a sandwich shop or coffee bar, to large institutional kitchens in hotels, hospitals or factories. Smaller kitchens, of course, take less time to diagnose the sources of German cockroach activity. Larger kitchens are more complex and thus more difficult to find all active harborages of cockroaches, but pest professionals can key on certain sites where cockroaches are most likely to occur.

POINTS OF MOISTURE. German cockroaches have a high need for water, so any site where a sink, plumbing or water accumulation exists needs to be checked. Commercial sinks should be inspected underneath and around plumbing penetrations and up under the splash guard on walls, as well as cracks and voids formed within the construction of the sinks and cracks behind baseboards. Dishwasher units likewise need similar investigation, as well as checking inside inspection panels of control boxes. Motor housings and the underneath and backside of coolers and freezers need to be checked.

POINTS OF FOOD. The stove/oven line and any prep table will be sites for activity due to the presence of food and grease deposits. On such equipment, inspect underneath for cracks and voids formed by the construction of stainless steel. Check wheels and legs on ovens and kitchen equipment and any electrical junction boxes. Look for cockroaches hiding in cracks behind baseboard tiles and stainless steel sheeting on walls.

POINTS OF SHELTER. German cockroaches prefer natural surfaces made of wood, paper and cardboard. Pest professionals should look for wood shelves, cabinets and wood bases, and check these areas for activity. Look for boxes stored at floor level in the kitchen and storerooms. Boxes with signs of water contact or stains should be checked for activity.

TOP THREE OVERLOOKED SITES. The following sites in commercial kitchens are the most common reasons for continued infestations. The time and effort needed to inspect/treat these sites is why they often go overlooked by professionals.

TARGET THROUGH INTERVIEWS. The fastest way to find where activity is located is by asking the kitchen staff to show you where they have seen and continue to see cockroaches.

Usually, the active harborages will be within a few feet of where they point. Sometimes, the infested sites are out of the ordinary, such as a can opener, meat slicer or knife rack on a wall.

Once you identify the key cockroach harborage sites in a commercial kitchen, control of the infestation becomes that much easier, but it requires regular communication with the kitchen staff, proving once again that customer communication and cooperation is key to successful cockroach control.

The author is owner of Stoy Pest Consulting and a frequent editorial contributor to PCT magazine.