In most US states, German, American, Oriental and brown-banded cockroaches are the most common home invading roach species, as all four are found throughout the contiguous US, and they are the only four roach pests found in much of the northern half of the country. However, in the southern states, several other cockroach species are well known for frequently establishing indoor infestations, some of which include Turkestan, Surinam, brown and Asian cockroaches. Of all cockroach pest species that inhabit only the southern half of the US, the Australian cockroach is the most common home invader.
A 2016 survey of pest control professionals in all US states found that the Australian cockroach was the fourth most commonly encountered roach within homes, which is surprising considering this species can only be found in the subtropical southeastern states. According to the survey’s results, the Australian cockroach was even more common than the brown-banded cockroach within homes. The Australian cockroach is the most common roach pests found in homes throughout Florida, and they are particularly abundant in southern Louisiana as well.
Australian cockroaches are of African origin, and they likely arrived in North America for the first time centuries ago by hitching rides on colonial slave ships. This species thrives in tropical and subtropical climates, and their lack of tolerance for cold weather motivates them to seek warm shelter within southeastern homes during the winter. Much like Oriental, smokybrown and American cockroaches, Australian cockroaches congregate in sewer systems where the warmth and abundance of food in the form of feces, dead skin, hair and rotting food scraps allow the pests to thrive. Unsurprisingly, Australian cockroaches are notable for thriving in pipes, sinks, septic lines, and they frequently appear in toilet bowls.
Residents of Louisiana often spot harmless non-pest cockroach species that accidentally wander indoors or fly toward artificial lights. It is important to avoid confusing Australian cockroaches with these non-pests, as Australian roaches spread numerous disease-causing microorganisms to human food sources and indoor surfaces by virtue of their filthy hangouts. Australian cockroaches resemble American cockroaches due to their relatively large 1 to 1 ½ inch body size and their reddish-brown to dark brown coloration. Unlike most cockroach pest species, Australian cockroaches are capable flyers.
Have you ever encountered cockroaches in your toilet bowl?