WSU Extension

Pestsense

Caption: Oriental Cockroach with egg case
Photo by: M. Bush
  
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Cockroaches

(revision date: 4/21/2021)


Use Integrated Pest Management (IPM) for successful pest management.

Biology
Cockroaches are flat insects that are found in a variety of colors. There are four common pest species: The German cockroach, the American cockroach, the brownbanded cockroach, and the Oriental cockroach. The German cockroach is most commonly found in the Pacific Northwest. Adult German cockroaches are 1/2 inch long, pale brown and have two dark brown lengthwise stripes on the shield behind the head. The American cockroach is reddish-brown to brown and is the largest of the cockroaches found in Washington, with adults reaching 1 1/2 inches long. The brownbanded roach is 1/2 to 5/8 inch long and is reddish-brown to dark brown with lighter bands across the wings. The Oriental roach is about 1 to 1 1/2 inches long, dark brown to black and has shorter wings. Cockroaches eat or contaminate human food and leave a persistent objectionable odor in infested areas. They are capable of mechanically transmitting disease and can cause allergic reactions. By nature cockroaches are nocturnal, so if you see any during the day it means the infestation is large.
Management Options

Non-Chemical Management
  • Always maintain a clean environment and do not let potential cockroach food accumulate in the open. Unwashed dishes, crumbs, spills, and uneaten pet food are attractive food sources for cockroaches. Keep trash cans and areas around and under sinks and appliances clean and dry.
  • Luggage, drink cartons, boxes, used appliances and furniture, and even grocery bags can carry cockroaches home. When returning from infested areas, check suspect items thoroughly for cockroaches and egg cases BEFORE bringing items into the home.
  • Roach motels or sticky traps are often used for monitoring populations; however, in single-family dwellings they can also be used for control.
Select non-chemical management options as your first choice!

Chemical Management
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides

Use listed products only where cockroach presence has been confirmed and only in conjunction with non-chemical management strategies including good sanitation. Be sure to target hiding places such as behind and under appliances, sinks, cabinets, etc. Baits are most effective if no other food sources are available and may require 7 days or more before control is noticed. Gel baits lose efficacy when dry, so they may need to be replaced regularly. Baits and growth regulators used concurrently are considered highly effective against cockroaches. Residual products such as Bayer Advanced Home Pest Control Indoor & Outdoor Insect Killer R-T-U will reduce the attractiveness and efficacy of baits and should not be used in the same vicinity as bait products. If you live in an apartment complex or other multiple-family dwelling, you may have difficulty gaining control of the problem since cockroaches can travel between units through spaces behind walls. Under these circumstances, hiring a professional pest management specialist would be advisable.

If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.
  • Raid Plus Egg Stoppers
    Active ingredient: hydroprene  |  EPA reg no: 4822-400
  • Combat Roach Killing Gel1
    Active ingredient: hydramethylnon  |  EPA reg no: 64240-35
  • Combat Source Kill Max R2
    Active ingredient: fipronil  |  EPA reg no: 64240-34
  • Raid Double Control Roach Baits (Large or Small)
    Active ingredient: Avermectin B1  |  EPA reg no: 4822-472
  • Ortho Home Defense Roach Bait
    Active ingredient: hydramethylnon  |  EPA reg no: 239-2730
  • This list may not include all products registered for this use.
Images
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Caption: Oriental Cockroach with egg case
Photo by: M. Bush
Caption: German cockroach
Photo by: unknown