10 Common Cockroaches in California

Common Cockroaches in California
Picture of Israel Alvarez
Israel Alvarez

Owner @ Insight Pest Management

Table of Contents

While California is home to a wide variety of dangerous pests, such as the black widow spider and rattlesnake, there is actually another California pest that can be much more dangerous to you and your family. Cockroaches are not only a known allergen for asthma, but they are capable of spreading numerous microorganisms, including staphylococcus, E. coli, and streptococcus, that can make you and your family very ill. In California, there are six main indoor cockroach species that you should be aware of, as well as numerous other species that, for the most part, remain outdoor nuisance pests.

Key takeaways

  • California is home to six cockroach species that are considered pests and are commonly found inside homes. There are also numerous other cockroach species in the state, but they are not interested in sharing space with you and very rarely venture indoors.
  • Cockroaches range in size from ½ inch to 2 inches or more in length and are nocturnal insects, meaning they are most active at night.
  • The most common cockroaches found inside Ventura County homes include the German, American, Oriental, Brown-banded, Smokey-Brown, and Turkestan.

Are cockroaches common in California?

Cockroaches are a very common pest found in all areas of California. While many species prefer to live outside and rarely venture into homes, there are six main species that are more than willing to share your home with you. Cockroaches are often found in sewer systems and areas where they come into contact with feces. As they explore your home and food, they are capable of spreading bacteria, such as Salmonella, which causes food poisoning. But that is only the beginning. These pests are capable of spreading many different bacteria and microorganisms, as well as allergens, that can make you and your family very ill. If you suspect a cockroach infestation, immediate professional pest control is recommended in order to eliminate this potential health hazard.

Types of cockroaches in California

California is home to a wide variety of cockroach species. While most cockroaches in California prefer to live outdoors and are not considered pests, there are six different cockroach species that can become very comfortable and even thrive living indoors, making them a top household pest. Learning how to identify these different cockroach species can help you determine whether or not you may have an infestation in your home or business.

German Cockroach

The German cockroach, Blattella germanica, is the most common indoor species found in California. They prefer warm, humid conditions and are most often found in bathrooms and kitchens in search of food, including pet food bowls. They prefer to live and breed indoors which can pose a serious threat to food contamination. They are light brown or tan in color and are one of the smallest cockroach species with a body length of around half an inch. This species has the highest reproductive cycle of the common cockroaches, with a single female able to produce over 30,000 new cockroaches each year, creating a large cockroach population. The German cockroach is a nocturnal species, so if you see one during the day, it is a good indication of an infestation and the time to call in professional exterminators.

American Cockroach

The American cockroach, Periplaneta americana, prefers warm, humid environments and is often found living in sewers. They will venture indoors around areas of leaking pipes. Because they often come into contact with human excrement, they are often the cause of food poisoning through the spread of Salmonella. The American cockroach is one of the largest cockroach pests with a body length of around two inches and is reddish-brown in color.

Oriental Cockroach

The oriental cockroach, Blatta orientalis, is often referred to as a water bug. It prefers cool, dark, and damp places, such as in garages, basements, and around water meter boxes. They are most often found inside single-family homes surrounded by vegetation. They often venture inside at night in search of food but are more likely to nest in outdoor areas around a water source or underneath a home. You may find them in the bathtub or sink drains. Unlike other cockroach species, oriental cockroaches are unable to climb smooth vertical surfaces, so when they get into a sink, they are often unable to get out. They are black to dark brown in appearance and measure slightly over an inch in length.

Brown-banded Cockroach

The brown-banded cockroach, Supella longipalpa, is not as common and only accounts for about one percent of home infestations in California. They prefer temperatures above 80°F and are commonly found in crevices near electrical appliances, such as refrigerators or stoves, and other areas of the home. They are not commonly found around food as they prefer starchy foods, such as the glue you find on stamps and envelopes. They are the smallest of indoor cockroaches, measuring 3/8ths to ½ inch in length. They get their name from their distinctive pale brown and darker brown alternating bands.

Turkestan Cockroach

The Turkestan cockroach, Shelfordella lateralis, is an invasive species that is quickly becoming a common California roach. Often referred to as the rusty red or red runner, these cockroaches are dark brown to black in color with red undertones and are around an inch in length. While they prefer to live outside near sources of food and water, they will venture inside. This is especially true of males, which often fly around at night and are attracted to light sources. You are most likely to find this cockroach species inside your home during the dry season.

Smoky-Brown Cockroach

The smoky-brown cockroach, Periplaneta fuliginosa, is usually found outside in vegetation and around sources of water and is an invasive species in California. When they invade homes, they prefer the upper areas of a building, such as an attic. They can also be found nesting under shingles or siding. They most often venture inside to escape colder temperatures or extreme heat and to look for food sources.

Western Wood Cockroach

Western wood cockroaches, Parcoblatta americana, are rarely found indoors and live predominately in grasslands or wooded areas. They are also known for seeking shelter and residing within harvester ant nests. They are reddish-brown in color and around half an inch in length.

Field Cockroach

The field cockroach, Blattella vaga, prefers to live outdoors and is most often found in plants and other vegetation. They can venture indoors when it becomes hot and dry outside. They are often mistaken for German cockroaches, but they are more olive in color and have a black stripe between their eyes.

Three-lined Roach

The three-lined roach, Luridiblatta trivittata, is native to Algeria, Libya, Morocco, and Spain, and was first detected in California in 2004. They can be found in the San Francisco Bay area as well as the central coastal areas of California. It is the smallest roach species in California and has three distinct stripes that run down the length of its body.

Surinam Cockroach

The Surinam cockroach, Pycnoscelus surinamensis, is also known as the greenhouse cockroach and is a burrowing cockroach. Adults are dark brown to black in color and are just under an inch in length. These roaches burrow in loose soil and are often brought into the area in tropical plant shipments. They feed on plants and are very destructive. In terms of finding them inside the house, this usually occurs when they hitch a ride in a new potted plant you brought into the home.

Australian Cockroach

Similar to the Surinam cockroach, the Australian cockroach, Periplaneta australasiae, is a tropical roach most often encountered in greenhouses. They resemble the American cockroach but can be distinguished by a cream-colored band along the forewing. They prefer warm and humid conditions and only venture inside during colder temperatures.

California is home to many cockroach species

While California is home to numerous different cockroach species, only a few are considered indoor nuisance pests. Being able to identify these common species can help you determine if the cockroach you saw scurrying across your floor is something to worry about in terms of an infestation or just another bug that wandered in to temporarily get away from the cold or heat. Keep in mind, however, that cockroaches are nocturnal so seeing one during the day can be a sign of a cockroach problem that needs immediate cockroach control.

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Keep your home and garden roach-free

Seeing a cockroach inside your home is enough to make your skin crawl, even if it is one that is unlikely to cause an indoor infestation. However, seeing one of these nocturnal creatures inside the home during the day can be a clear sign there may be trouble.

If you suspect a cockroach infestation, the team at Insight Pest Management is here to help. Our expert technicians will identify which species of cockroach is causing problems, develop an individualized treatment plan, and, once eradicated, help you keep your home or business cockroach-free.

To learn more, request an appointment today.

Serving all of Ventura County

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Our expert technicians work to ensure that all potential pest entry points are sealed and offer routine treatment options to help ensure your home or business stays protected from future infestations. You don’t have to share your home or business with pests any longer! If you live in the Ventura County area, let the team at Insight Pest Management help you say goodbye to pests once and for all!

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