Cockroaches are among the oldest living organisms on the planet, as experts state that these insects existed long before the dinosaurs made their appearance on earth. Researchers estimate that cockroaches emerged around 350 million years ago, and recent genetic studies have confirmed that termites directly descended from early wood-eating cockroaches. Today, there are around 4,500 cockroach species worldwide, most of which maintain tropical habitats where they never make contact with humans. Only 70 cockroach species can be found in the United States today, and most of them are not considered pests.

Around a dozen cockroach species throughout the country are considered significant pests of homes and buildings, and the most common, the most abundant and the most frequently encountered species within homes include German, American, Oriental and brown-banded cockroaches. These cockroaches are the dominant cockroach house pests in just about every state, but surprisingly, none of these species could be found in North America until somewhat recently. In fact, it could be said that cockroach pest species should not exist in the US at all, as every roach pest in the US is a non-native species that was accidentally transported into the country.

Of the four dominant cockroach pest species, many researchers believe that the American species was the first to arrive in the US. Given their common name, many people believe that the large 2 inch American cockroach must be native to the US, but researchers state that this species is native to tropical Africa, and it first made its way into North America on slave ships a few centuries ago. After the American cockroaches species’ unwelcome arrival on the continent, the German and Oriental species followed shortly after. With the exception of the less abundant brown-banded cockroach, the German cockroach is the only roach species that has adapted to survive solely within homes and buildings, making this species the most common, the most stubborn, the most medically hazardous, and the most insecticide-resistant cockroach species that has come to inhabit the US. Cockroach species in the US that are non-pests, are all native, while all roach pests in the country are non-native. To this day, new non-native cockroach species are still being inadvertently introduced into the US, including Asian and Japanese cockroaches.

Have you ever spotted a roach within your home that you were unable to accurately identify?