Bug Blog

Finding Sewer Cockroaches Within Homes Is Not Uncommon In Southern Arizona

Several cockroach pest species infest homes in all areas of the contiguous United States. The four most common species are American, German, brown-banded, and Oriental cockroaches, and each one of these species can be found throughout the country. The south is home to a few additional cockroach pest species, most notably the Australian and smokybrown cockroaches. Like virtually all insects, cockroaches are heavily dependent on moisture in order to survive, so it is not surprising that most cockroach pest species inhabit the southeast. While southern Arizona is an arid desert landscape that sees only a few inches of rainfall annually, a relatively high number of cockroach pest species thrive in the region. These species include field, Surinam and Turkestan cockroaches, the last of which has become particularly abundant since its relatively recent introduction into Arizona back in the early 1980s.

While Turkestan cockroaches have become very common pests in Tucson and Phoenix, the German cockroach is easily the most commonly encountered and most frequently controlled cockroach pest in Arizona homes, and the country as a whole. Along with the brown-banded cockroach, the German cockroach is a domestic pest, which means that it is one of the very few pest species that dwells primarily in homes and buildings. The brown-banded cockroach is the least common of the four primary cockroach pest species due to its relatively recent introduction into the US, which occurred nearly 150 years after the American cockroaches’ first appearance in the country. Brown-banded cockroach populations have also been declining for reasons that are not well understood by researchers.

With the exception of the German cockroach, the large American cockroach is the most commonly encountered roach pest species in southern Arizona homes. Adults of this species are between 1 ¼ to 2 or more inches in length, and they are notable for inhabiting sewer systems in massive numbers in urban centers throughout the US, including Tucson and Phoenix. On one occasion more than 5,000 American cockroaches were found in a single manhole, and unfortunately, these filthy pests have been known to travel from sewers and up through pipes and into homes through drains. Pima County and other counties in the state run their own sewer-cockroach abatement program. The county carries out many cockroach control operations, and the Conveyance Division treats all manholes in the county for cockroach pests every other year.

Have you ever found one or more cockroaches in your home that you suspected had originated from the sewer?