Cockroaches in
Washington

Last Updated: July 5, 2021

Cockroaches in
Washington

Last Updated: July 5, 2021

Cockroaches have gained quite the reputation (did you know they are one of the most commonly feared insects on Earth?). They’re known for their resilience against the elements, and as a pest that is difficult to get rid of. This, in part, is true. But much of their stubbornness depends on whether their environment will support them. By using tried and true treatment methods, it is possible to tackle even the worst infestations. In this article, we’ll discuss the four types of Cockroaches we have here in the Pacific Northwest, their behavior, and how you can stop them from invading your home.

Table of Contents

Cockroach Vocabulary

Ootheca(e) (“Oo-THeh-cuh”): The egg cases or containers that Cockroaches use to store their eggs.

Harborage: Any place that provides cover, protection, or room for nest building. For example, excess vegetation or piles of items.

Molt: The process in which a Cockroach grows too large for its body, and must shed away the smaller shell in order to become larger. This term can be applied to many insects.

Nymph: An immature Cockroach that has not finished growing. This term can be applied to many insects.

General Information and Life Cycle

Cockroaches mature by simple metamorphosis, meaning that they transition through three phases: egg, nymph, and then adult. Because of this, cockroaches can be quite pervasive, but usually easy to identify regardless of what stage they’re in. They are able to reproduce throughout the year, resulting in overlapping generations, making it possible to find a Cockroach in any of the three stages at any time.

An important thing to note about Cockroaches in Washington is that they are indoor pests only. Should an outdoor infestation persist, this usually means that the interior infestation has reached an extreme level. Exterior treatments are rarely needed.

When ready, females deposit their eggs in bean-shaped or purse-like egg cases called oothecae. Each species creates a unique ootheca. The number of eggs per egg case depends on the species, but can be anywhere from 16 to 48 eggs. Nymphs hatch from the eggs, and immediately resemble their adult counterparts. However, they are smaller and usually slightly different in color. Their wings, if they have them, will be underdeveloped.

Nymphs grow progressively as they age. Each growth state ends with a molt. It takes anywhere from 5 to 13 molts before a nymph is fully mature. The span of time between each molt varies, as each of the four species of Cockroaches observed in Western Washington have different growth rates.

An important thing to remember about Cockroaches is the old adage: “When there’s one, there’s a hundred.” Generally, seeing a Cockroach is indicative of a larger infestation. Cockroaches are nocturnal. If you see one during the day, it’s likely that they have run out of room to hide anywhere else. 

You can read more about how Cockroaches survive without their heads here.

Fun Fact:

 Cockroaches can survive for a week or more without a head!

You should always contact a Pest Control professional if you suspect there may be a problem. Keep an eye out for:

  • Frequent Cockroach appearances. The biggest telltale sign of an infestation is actually seeing a Cockroach.
  • Droppings. Cockroach droppings are small and pepper-like in appearance.
  • Living conditions. What is the environment like? If there are unsanitary conditions that have been around for a while, it’s likely there may be an infestation.

German Cockroach

German Cockroaches are pretty small, usually measuring about ⅝ inch in length (or smaller). Adults are pale brown with two dark brown lengthwise stripes on the shield or plate behind their head. While they do have wings, they rarely fly. Adults can live up to 12 months in ideal conditions.

German Cockroach egg cases are slender, about ⅓ inch long, and a light tan. They are carried by the female Cockroach until roughly two days before the eggs are ready to hatch. This is the only species in our area that will carry the ootheca this long. Each case contains 30 to 48 eggs. A female will produce 4 to 8 ootheca during her lifetime. This, combined with the sheer number of eggs per case, make control of German Cockroaches difficult. 

German Cockroach nymphs are darker than adults and have a single pale brown stripe separating two darker brown strips that run about halfway down their body. The nymphal stage lasts 1 ½ to 4 months. 

This species is the most common in our area. While they can infest many different locations, they’re commonly found in apartments, restaurants, hospitals, or other buildings where food is stored in large quantities. They are less common in private homes.

Infestations can begin accidentally and progress quickly. German Cockroaches may be carried into the home or structure inside electronics, appliances, groceries, or furniture. Make sure you thoroughly check items that are brought to your home, especially if you are buying used. Pay special attention to your kitchen– this is where you will most commonly find them if you have an infestation. 

During the day, German Cockroaches stay hidden. Adults and nymphs will huddle together underneath or behind stoves, refrigerators, sinks, or cabinets. Depending on the severity of the infestation, you might find them anywhere there is space that isn’t already occupied

Brown Banded Cockroach

When it comes to size, Brown Banded Cockroaches are almost identical to German Cockroaches. The major difference is that the Brown Banded Cockroach does not have a striped shield behind its head. Females have short wings that never fully cover their abdomen.

Males’ wings are much longer, covering or extending beyond their abdomen. Male Brown Banded Cockroaches can and will fly.

Egg cases are a light, reddish brown, no more than ¼ inch long. Females produce 10-20 ootheca in their lifetime, each containing 16 eggs. You can find the ootheca attached in clusters to furniture, curtains, shelves, or ceilings. 

Brown Banded Cockroach nymphs can be identified easily by their two traverse yellow bands near their head. The nymphal stage lasts about 3 to 6 months. Adults live 3 to 11 months on average.

This species is most likely to be found in private residences, yet is much more prevalent in Eastern Washington. Both adults and nymphs prefer warm areas and can be found behind wall decorations, loose wallpaper, inside closets, or within electronics. Because of this, a very thorough treatment is needed to handle an infestation.

Oriental Cockroach

Oriental Cockroaches are larger than ⅝ inch with wings shorter than their abdomen. In fact, females can be identified because they do not have wings, and are about ¼ inch larger than males. They are a deep brown-to-black color. Adults can live for 1 to 6 months in ideal conditions.

Egg cases are a dark, reddish brown, and about ½ inch long. They are slightly puffy or inflated. A female will produce 8 to 15 egg cases in her lifetime, each containing 16 eggs. Typically, the female will deposit them in warm, sheltered locations near a food supply. 

Nymphs are the same color as the adults. While they will eat just about anything, they mostly feed on decaying organic matter. The nymphal stage lasts about 1 year, and consists of roughly 7 molts. 

While this species is tolerant of cooler temperatures, they thrive in warm, humid environments. They have been recorded as a seasonal pest, appearing in the Spring and Summer. Oriental Cockroaches are generally uncommon in Washington. 

American Cockroach

American Cockroaches are much larger than the other three species we’ve covered. In fact, it is the largest of all house-infesting Cockroaches, averaging around 1 ½ to 2 inches in length. They have wings that cover their abdomen, often longer. .

Color-wise they are not normally darker than a chestnut color with a light yellow or tan band around the edge of the shield behind their head. Both males and females develop wings, but rarely fly. Males can be identified by their longer wings which usually extend past the length of their bodies.

Ootheca are dark brown and about ⅓ inch long. Females deposit ootheca in sheltered areas on or near the floor. Cases are formed at a rate of 1 per week until 15-20 have been produced. Each one contains 16 eggs.

Nymphs are grayish-brown-to-brown and become more reddish as they grow. This stage lasts 5 to 15 months. Once they are fully matured, adults can live up to 15 months on average.

American Cockroaches are fairly rare in Western Washington. They prefer warm, moist environments such as sewers, boiler rooms, or around bathtubs. Like many Cockroach species, they thrive in environments where food is stored and readily available.

What causes an infestation?

Environmental controls play a big role in cockroach infestations. Regardless of the species, cockroaches will thrive in places with both harborage or hiding spots and poor sanitation. During the inspection process, it is important that all hidey-spots are located. Cleanup aids considerably in this process.

In apartment buildings, there is usually one “seed” unit that is the causal force behind the infestation. This is bad news for neighboring renters. Cockroaches will multiply until they run out of room, which is when you begin to see them crawling around in the open. They will happily invade nearby residences, invited or not.

Prevention Tips

  • Keep your home clean and prioritize sanitation, especially if you live in an area with a large Cockroach population.
  • Make sure foodstuffs are sealed in pest-safe containers.
  • Check hard to reach areas, such as beneath kitchen appliances, for activity. 

How Sunrise Can Help

Here at Sunrise Pest Management, we have developed a specific service to tackle a Cockroach infestation in homes, apartments, or commercial sites. Our licensed Technicians are trained to complete a multi-step, thorough process that combines a wide array of inspection and treatment techniques. We have to go beyond just treating infestations with chemicals, which is why it’s always best to seek the help of a professional.

In addition to our specific service for Cockroach control, we offer a maintenance service to help with all kinds of pests, including Beetles and Moths. All Pest Protection is a quarterly maintenance service aimed to prevent infestations of general pests such as Carpenter Ants, Rodents, Bees, and other insects. 

We come out on a 3-month rotation to provide an exterior perimeter spray where the home and foundation meet, spot treat around doors and windows for activity, sweep reachable webs and Spider egg sacs, and maintain Rodent Bait Stations (secured, locked, black plastic boxes) on the exterior of the home to mitigate outside Rodent populations.

All Pest Protection (APP) also can include various warranties for general pests, which are established after the Initial Inspection and Treatment. Once you get started, each quarterly service is only $99 before tax. Should your house be overrun by Fleas, Bees, or Spiders, or any of the pests eligible under your warranty, all you would have to do is give us a call. We’ll dispatch a Technician to complete a pest-specific treatment at no cost to you under your APP Warranty.

Sources

“American Cockroach.” Plant & Pest Diagnostics, Michigan State University, www.canr.msu.edu/resources/american-cockroach.

Antonelli, Arthur L. Pest Management Study Manual for Pest Control Professionals. Washington State University Extension, 2016.

Choi, Charles. Fact or Fiction?: A Cockroach Can Live without Its Head, Scientific American, 15 Mar. 2007.

McCanless, Kim. “Featured Creatures: Oriental Cockroach.” Oriental Cockroach – Blatta Orientalis Linnaeus, 2000, entnemdept.ufl.edu/creatures/urban/roaches/oriental_cockroach.htm.

Piper, Ph.D., G.L., and A.L. Antonelli, Ph.D. “Cockroaches: Identification, Biology, and Control.” Pacific Northwest Cooperative Extension Publication Washington/Oregon/Idaho, no. 186, 1997, pp. 3–8. 

About the Authors

This article was created and edited in collaboration with multiple licensed pest control technicians, experts, researchers, and authors.

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