Species of cockroaches in Canada
Cockroaches (Order: Blattodea) are among the oldest and most successful groups of insects in the world, possibly dating to about 350 million years ago. They are a common pest found inside homes, restaurants, apartments and commercial buildings. Known to sometimes carry diseases, they can cause salmonella, asthma, allergy attacks, and much more. Most species of cockroaches have wings but are unable to fly. They prefer to live in warm and humid environments, where they feed on leftover food, decaying organic matter, grease, wallpaper paste, bookbinding and paint.
There are three species of cockroaches commonly found in Canada: the German cockroach, American cockroach, and Oriental cockroach.
German cockroach (Blattella germanica)
The German cockroach (Blattella germanica ) is the most widely distributed and among the most difficult to treat. In addition to stealing/contaminating food, damaging clothing, and destroying appliances such as computers, they are also capable of spreading diseases.
The adult German cockroach has a flat oval dorsal and abdomen that is divided into three parts: the head, thorax, and abdomen. The younger ones are only 0.2 to 0.5 cm in length, while most adults are 1 to 3 cm long. They are yellowish-brown, reddish-brown or dark brown, varying from species to species; the body surface generally has a noticeable luster. Early-instar (period between each molt) nymphs are dark brown or black, wingless, with two prominent stripes on the thorax (pronotum) behind the head.
Habitat and behaviour
The German cockroach originated in the hot and humid environments found in Africa, and prefers to live in similar environments here. Nymphs have the same habits as adults and are negative phototaxis insects. They hide in warm, moist and dark places during the day, such as walls, ceilings, and furniture, but mostly prefer hiding in the kitchen where they can stay warm behind a fridge and scavenge for food. They are nocturnal, and may come out at night to find food, water and mates.
The German cockroach is an omnivorous scavenger. They will eat a variety of food regardless of whether nor not they are spoiled, including human hair and sputum. If there is access to food and water, adults can survive for more than a month; otherwise, it will not exceed two weeks, and the group may resort to cannibalism. Alternatively, they may scatter and find another place to invade.
American cockroach (Periplaneta americana)
Adults of American cockroaches can average about 4 cm in length. They have long, flat and wide bodies, with a reddish-brown colored exoskeleton, and a light-brown hue to the yellow band on their thorax. American cockroach nymphs are similar to adults except they have no wings.
Like most cockroaches, American cockroaches usually live in humid places, but if they are in dry areas close to water, they can still survive. In areas where people live, American cockroaches often nest in shady places such as basements and sewers, however they may run outside sometimes to breathe after spending too long indoors.
Oriental cockroach (Blatta orientalis)
Adults of this species are oblong, 2.5 cm long and dark brown. The head is a flat triangle and hidden under the chest are long filamentous antennae. The male wings do not completely cover the abdomen, and the female wings degenerate into two small pieces.
Habitat and behaviour
The oriental cockroach is a household species, but it is also found outdoors. It prefers a cooler environment than the aforementioned German and American cockroaches (areas of around 20-29 degrees Celsius). They often live in basements, cellars, roofs, drainage pipes, sewage ditches, and wall cracks.
It is omnivorous, mainly damaging grains, paper, leather, books, clothing, and other fabrics. Their excretion can contaminate various articles and spread diseases.
Signs of cockroach infestations
Shed skin – Check for signs of molted skin in locations where they would usually be sheltered. Cockroaches shed their skin 6-7 times as they develop into adults.
Cockroach droppings – They produce black droppings that are less than 1 mm wide.
Smear marks – Check for smear marks where you suspect them to be active.
Damage – Look for signs of damage on food packaging, papers and fabrics.
Unusual odour – Cockroach infestations also produce an unpleasant smell..
Look for cockroaches in your kitchens, bathrooms and basement – German cockroaches prefer to live in warm and humid conditions, most notably in kitchens behind the fridge or ovens, in the bathrooms, or cracks in walls/furniture where they would be insulated.