American Cockroach, Vol. 5, No. 25
This is the roach people are talking about when they “brag” about the size of roaches they have seen. American cockroaches are the largest roaches in the state, with some specimens reaching 2 inches in length. They are also our fastest cockroach. If you ever decide to enter a contestant in a cockroach race, get a large American cockroach. This is one of the fastest insects in the world.
American cockroaches, along with brown and smoky brown cockroaches, are important pests throughout the state. Collectively, these three species are referred to as “large cockroaches” to distinguish them from the smaller, but more problematic, German cockroaches because there are important differences in the biology and control of these two groups. You won’t find American cockroaches living out in the woods and fields; they prefer to live in close association with humans. But unlike German cockroaches, which only live indoors, American cockroaches are often found living around the outsides of buildings, as well as in sewer drains and around other man-made structures. They will also readily invade homes and commercial buildings and breed indoors when conditions are suitable.
American cockroaches are not native to the US, but they have been here ever since the country was colonized by Europeans. Because they thrive on ships, they now occur worldwide, having been carried to every port in the world and then spreading into the interior of the country. These are also unusually long-lived insects, taking around 1.5 years to develop from egg to adult and then living as adults for up to 2 years. The eggs are produced in special purse-like cases, called ootheca, that contain 16 eggs which hatch simultaneously. According to Dr. Coby Schal, female American cockroaches produce an average of 21 ootheca during their life. Let’s see, 16 x 21, that’s more than 300 little cockroach nymphs per female.
Control: Exclusion and “sanitation” are key first steps in the prevention and control of American and smoky brown cockroaches. Door sweeps, close-fitting thresholds, weather stripping around doors and windows, and sealing other cracks and potential entry points greatly reduce the number of large cockroaches, spiders and other “occasional invaders” that get inside. Reducing harborage and food sources for cockroaches around the outside of the building is the next key step. This includes things like keeping outdoor garbage cans and recycling containers tightly covered, avoiding free-choice feeding of pets, keeping pet food in bug-proof containers, removing piles of debris or stacks of lumber, avoiding vines growing on buildings, and similar steps. Insecticides applied as baits or exterior perimeter sprays are also useful but work best in combination with cultural practices that make areas less favorable to cockroaches.
See Extension Publication 3346, Control Cockroaches in and Around Your Home, for more detailed information on cockroaches and cockroach control.
Blake Layton, Extension Entomology Specialist, Mississippi State University Extension Service. The information given here is for educational purposes only. Always read and follow current label directions. Specific commercial products are mentioned as examples only and reference to specific products or trade names is made with the understanding that no discrimination is intended to other products that may also be suitable and appropriately labeled.
Mississippi State University is an equal opportunity institution.