Most of the cockroach species people commonly encounter in their homes are not native to North America, but the continent is home to many indigenous species. The small, fast-moving insects seen scattering across a kitchen floor are usually foreign invaders that have adapted to human structures. These introduced pest species have leveraged global commerce and human habitation to establish themselves across the continent.
Defining Native and Introduced Species
A species is considered native, or indigenous, if it originated and naturally evolved within a specific geographic region without human intervention. Native species have adapted over millennia to the local environment, becoming integral parts of the natural ecosystem. Conversely, an introduced or non-native species is one that has been transported to a new location through human activity, either intentionally or accidentally. Those introduced species that establish a growing population and cause ecological or economic damage are then categorized as invasive species. The most problematic cockroaches in North America thrive in human dwellings because they lack the natural controls of their native lands.
The Major Pest Species Are Not Native
The cockroaches that cause the most concern for homeowners are all imports, having arrived via global shipping routes over the centuries.
German Cockroach (Blattella germanica)
The German Cockroach, the most common indoor pest, did not originate in Germany. Genomic analysis suggests it evolved from the Asian cockroach (Blattella asahinai) around 2,100 years ago, likely in India or Myanmar. This small, light-brown species relies entirely on human structures for survival and was dispersed globally through commerce and transport.
American Cockroach (Periplaneta americana)
The American Cockroach is also a misnomer, as it is native to Africa and the Middle East. This large, reddish-brown species arrived in North America as early as the 17th century, likely stowing away on ships involved in transatlantic trade. It prefers warm, moist environments like sewers, steam tunnels, and food preparation areas, making it a common pest in urban infrastructure.
Oriental Cockroach (Blatta orientalis)
The Oriental Cockroach is often called a “water bug” due to its preference for damp areas. This dark brown to black species is believed to have originated in Africa or possibly southern Russia. It thrives in cool, damp locations like basements, crawl spaces, and sewer systems. All three of these species are synanthropic, meaning they closely associate with and benefit from human habitats.
Identifying North America’s True Native Cockroaches
North America is home to numerous native cockroach species that are primarily outdoor dwellers. These indigenous roaches play a beneficial role in the ecosystem, acting as detritivores by consuming decaying wood and leaf litter, which helps cycle nutrients back into the soil. They are not considered pests because they cannot reproduce or survive long-term inside the dry, sterile conditions of a human home.
Pennsylvania Wood Cockroach (Parcoblatta pensylvanica)
This species is native to the eastern and central United States. These roaches are found in forested areas, living under loose bark, in woodpiles, or in hollow trees. Males are strong flyers and are frequently attracted to outdoor lights at night, which is often how they accidentally enter homes.
Florida Woods Cockroach (Eurycotis floridana)
Also known regionally as the Palmetto Bug, this large, slow-moving cockroach is native to the southeastern United States. It thrives in warm, humid environments, often found under leaf litter and in vegetation. Unlike introduced pests, this cockroach occasionally emits a foul-smelling defensive fluid when disturbed, and neither sex possesses fully developed wings for flying.