GardenLine | Common Saskatchewan Pests | Kitchen and House Pests

Lynn is an information officer for Canada Agriculture. This column is provided as an extension service by the Division of Extension and Community Relations and the Department of Horticulture Science, University of Saskatchewan.

Cockroaches, larder beetles and carpet beetles are among the more persistent house pests. Your three best allies for ridding your house of these uninvited guests are planning, patience and persistence.

Cockroaches
German cockroach

The German cockroach (Blatella germanica) is the most common cockroach you will find in Saskatoon. It is about 12.5mm in length, brown in colour, with two dark streaks on the area just behind the ahead. Adults are winged but the nymphs are wingless. They have two small projections on the end of their abdomens. They move quickly and prefer the dark. If you see them in light, there are usually many somewhere close by.

The cockroach develops from an egg to the nymph stage, them to adulthood. From egg to adult takes about 3 to 4 months, and the adults may live for up to 1 year. The female lays about 30 to 40 eggs and wraps them in a "packet", which she expels. The young work their way out of the packet in a few hours. The female lays 4 to 8 packets in her lifetime.

Cockroaches arrive in a house or dwelling usually by hitching a ride. The carrier will most likely be a cardboard box which was stored in warehouse infested with cockroaches or any other carton or container which could contain the egg packet of the female cockroach. Therefore, be wary about bringing boxes into your home which may come from cockroach-infested places. Unpack such boxes in a garage where egg packets or cockroaches can be seen and killed with an insecticide. Use insecticides inside the house only when all other measures fail.

If cockroaches do invade your dwelling, take steps immediately. Clean up all foodstuffs daily to reduce their feeding sources. If you have pets, don't keep the pet food out all the time. Clean up around pet bowls. Use items called "cockroach hotels." They are stick-coated, upon-ended paper containers you place in dark areas near baseboards or under stairways, shelves or other hiding places. The cockroach literally sticks to the substance and dies. Keep all foodstuffs in sealed containers. If all this fails, contact a professional exterminator or pick up literature on sprays for roaches and follow directions very carefully.

Larder beetle

They usually enter your home with dog or cat food. The beetle is 11 to 13 mm in length, dark brown to gray in colour, with a characteristic spotted, yellow-cream coloured band across the wing covers. The larvae is brownish in colour, 11 to 13 mm in length. It has tow characteristic curved spines on the abdomen end of its body.

Larder beetles may complete their life cycle from egg to larvae often through to adult beetle in about 60 days, but often in a house they will take twice as long due to the lower temperature we experience in this part of North America. They live outside during the summer and migrate into the house in the fall.

Larder beetles move slowly both as adults and larvae. They stay in dark places most of the time and may be found in any room of the house. They will feed on most protein-containing foodstuffs, including pet and human hairs, dead plies and feathers. Pet food is made to order for their diet.

Control of this insect is relatively easy. Keep foodstuffs away from it. Vacuum the floors two to three times a week to eliminate pet and human hairs, and clean the pet food area daily. Store dry pet food in the garage or outside. If your pet stops eating check its food, which could contain the larder beetle larvae or adult.

Carpet Beetles Black carpet beetle

The black carpet beetle is the most common species we see in Saskatoon. As an adult it may live outdoors, where it will feed on the pollen of flowers. In your house, it may be found in floor cracks, behind baseboards, under carpets, in cupboards and even in air ducts.

The adult is 2.8 to 5 mm long, and dark brown or black in colour. The larvae is long and narrow, up to 7 to 8 mm in length, excluding the long characteristic tuft of hairs on the end of it's abdomen. The short, stiff hairs on its body segments are a dark brown and gold in colour. When the larvae is disturbed, it curls up and "plays possum."

The egg of the carpet beetle is very fragile. It hatches within 5-16 days depending on temperature. The larval stage is the longest period of the life cycle of the beetle, 250 to 640 days depending on food, temperature an humidity. Overall, their complete life cycle takes about 9 months.

You can control this insect is by frequent vacuumings. Since the larvae do like light, make sure you vacuum where they will most likely be, near baseboards and under furniture. If you have to use an insecticide, apply it behind the baseboards or perimeters of rooms and closets. See a professional exterminator if you don't have the proper equipment or if you are apprehensive about spraying by yourself.

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Sustainable horticultural information, offered free of charge to the public with the support of the University of Saskatchewan Extension Division, the Department of Plant Sciences and the Provincial Government.