The Usual Bug-spects

A cockroach is a cockroach no matter where you are, so they are all treated the same, right?

Wrong.

Where you are and what cockroach you are dealing with makes a big difference in your treatment. Specifically, there are several important differences between cockroaches in residential and commercial environments.

There will always be some exception to the rule, but generally cockroaches stick to these environments. Some of the most common ones that PMPs may encounter include the American, smokeybrown, brownbanded, Oriental, German, Turkestan and Asian cockroaches. Depending on what area of the world or even region of a country you serve, the kinds of cockroaches you commonly deal with can vary. Knowing the roaches in your service area and which ones are found in commercial versus residential settings will set you up for success in the field.

As in any insect Integrated Pest Management (IPM) program, there are three conducive conditions we are inspecting for to properly treat and eliminate cockroaches: food, water and shelter, otherwise known as the “pest triangle.”

These conducive conditions look different for every cockroach and whether you’re controlling them in a commercial or residential setting. When we think of commercial pest control, rodents may be the first pest we think of, not roaches.

That too can be case dependent. For instance, consider the differences in pest concerns for a restaurant compared with a baseball stadium. Cockroaches are most common in environments with food. They are prominent in kitchens, bathrooms, food servicing areas, etc. The most common cockroaches in commercial settings are German and American cockroaches.

The German cockroach is one of the most economically important cockroach pest species. In a commercial setting, they are both prominent and a problem. Typically found in food service accounts or in break rooms of non-food commercial accounts, they often hide in warm, moist areas with access to food and water.

German cockroaches have the fastest reproduction rate among all cockroach species, with the highest number of eggs per ootheca, the cockroach egg case. Adult German roaches are 1/2 to 5/8 of an inch long and pale to medium brown in color with two stripes on their pronotum.

Given the German cockroach’s ability to reproduce quickly, this roach species can be hard to control. It is important to locate where the fecal focal points are found. Typically characterized by a large number of young nymphs, fecal focal points are where most of the colony can be found. These can be determined by monitoring with glueboards. The life stage(s) and number of cockroaches on a glueboard will give an indication of the proximity to a fecal focal point.

For example, if you were to collect a completely covered glueboard with a majority of nymphs, you are less than a foot from a fecal focal point because the immature and young nymphal stages do not forage far from these areas. The best control methods for German cockroaches include baits and insect growth regulators (IGRs).

Removing harborage is also important. Often, German cockroaches are carried in through cardboard boxes with food that a customer has bought. Since German cockroach problems are generally brought in, eliminating cardboard boxes is key to helping control the colony.

American cockroaches are the other species commonly found in a commercial setting. Unlike German roaches, they favor a different kind of habitat. They prefer warm, moist places such as sewers.

While German cockroaches are commonly found in kitchens, American cockroaches are found in bathrooms and areas containing drains. They may come up through drains and toilets that are left to dry out. Without water in the P-trap, they can gain easy access to a facility. American cockroaches are the largest of the common species of cockroaches, growing to 1 ½ inches in length, and are reddish-brown in color. They can be identified by a Batman-shaped symbol on their thorax.

Because of the habits of American cockroaches, their treatment will be different than that of German cockroaches. Drain cleaning and treatment may help — but making sure that toilets and drains have ample water in them is the first step.

Granular baits are best for these cockroaches and can be applied outside or in bait stations. We must be careful not to apply pesticide down drains when a product is not labeled as such. Where a drain leads to is often unknown, and we do not want to cause unwanted contamination.

German and American cockroaches are also commonly seen in residential settings, and their treatment is generally the same. However, residential settings mean potentially more species of cockroaches to address depending on where you are in the world.

The best way to distinguish differences and treatments would be to understand the difference between peridomestic and domestic cockroaches. Peridomestic cockroaches live and breed outdoors. Among the common cockroaches, American, Australian, Oriental, Turkestan and smokeybrown are considered peridomestic.

Here’s how to identify them.

• American: These are reddish brown and have a Batman-shaped pale-yellow marking on their pronotum. They are 1-1 ½ inches long and capable of flight. These roaches are often found in damp, moist areas such as sewers, drains and toilets.
• Australian: They are roughly 1 ¼ -1 ½ inches long, range in color from reddish brown to dark brown and have fully developed wings capable of flight. They have distinct yellow bands on the outer edges of both of their wings.
• Oriental: These are 1 inch long and dark brown to black in color. Males have wings that cover three-quarters of their body and have small pads. Males and females are both flightless and like to live in warm, damp and shady areas near the ground. They are commonly found in basements.
• Turkestan: These are dimorphic (females and males look different). Females are 1 inch long, dark brown to black in color and have cream-colored markings on their wing bud margins. Males are slightly smaller than females with yellowish-tan wings and cream-colored stripes on the edges. They are commonly found in wood piles and near irrigation and water meter boxes. They prefer dark, moist hiding places and come out at night to feed.
• Smokeybrown: These are black to mahogany in color. They are approximately 1 ½ inches long and are strong flyers. They are often found in leaf litter and mulch, and their coloration hides them.

The other group of cockroaches that are seen in residential settings are domestic cockroaches. These include German and brownbanded cockroaches.

• German: These cockroaches are ½ to ¾ of an inch long and brown to dark brown in color with two distinct parallel bands running the length of their pronotum. They have a thin, slender body and are incapable of flight. They are often found in moist, warm areas in the home such as the kitchen and bathroom.
• Brownbanded: The brownbanded cockroach resembles the German cockroach in size and shape but can be distinguished by the absence of the two dark stripes. They are 1/2 to 3/4 of an inch in length, capable of flight and have two horizontal stripes that can be found close to the wings. They are usually found anywhere around the house.

CONTROL STRATEGIES. Control methods are dependent on the group of cockroaches. For peridomestic cockroaches, treatment should be more focused on the outdoor perimeter of the home. This group of cockroaches lives and breeds outdoors and is found inside because they are in search of food or water.

Perimeter treatment with liquid or granular products will help prevent pest cockroaches from entering the home. Other methods of control would be more physical or mechanical in nature. Such methods include sanitation, eliminating any debris, liquids or waste that would be conducive to these cockroaches. If sanitation is not possible in a given area, you can bait with a granular bait or insecticide.

Peridomestic cockroaches are nocturnal and very attracted to outdoor lights. This attraction often leads them to find their way indoors. These lights should be used sparingly when opening doors.

The final non-chemical control method is exclusion. How are these outdoor cockroaches getting inside, besides a door or window? They will get in through cracks and crevices that lead into the home. These include door sweeps, windowsills and any other small areas.

For domestics, the controls are different since these two species can live and breed indoors. The first step to control them would be to locate fecal focal points. This helps to determine where the cockroaches are and where to focus treatment. Baits and IGRs are the best treatment methods.

A HEPA vacuum may also be used to lower cockroach populations prior to treatment or after initial baiting. Inspect for cockroaches and their egg cases, which are often on furniture within the home if brownbanded roaches are present. Removing egg cases is an important step to controlling current and future populations.

Cockroaches, whether in a commercial or residential setting, are important to control. They can carry histamines and diseases, which make them a health risk. It is critical to identify the cockroach you are dealing with to select the control method.

While commercial and residential locations may require different treatments, the overall process is the same. Start with inspection, then monitor and identify the pest to choose the proper control methods. No account or customer is the same, so take time to inspect, learn what pest(s) are present and do the job the right way, the first time.

The author is director of training at Cook’s Pest Control.