Rana Sarfraz: How to get rid of cockroaches
Cockroach infestations are common in homes, offices, schools, hotels, restaurants, grocery stores, and food-processing facilities throughout the Lower Mainland. Vancouver General Hospital’s kitchen had to deal with a cockroach problem twice last year. Imagine the beasts crawling over and excreting on everything in your favorite restaurants’ kitchen after having travelled through garbage and sewers. Gross!
The German cockroach is one of the most common household cockroaches in the world, including British Columbia. Adult roaches are about 1.3 to 1.6 centimetres long and tan to light brown with two dark parallel lines running from the head to the base of the wings. They have fully developed wings, but are unable to sustain flight.
German cockroaches are drawn to moist environments (e.g. kitchens, bathrooms, basements and plumbing areas) and are fond of starches, sweets, grease, and meat products. As with other species, German cockroaches are most active at night and may go unnoticed for some time.
Cockroaches contaminate food and spread disease by walking over, and excreting on, food or food preparation areas after having travelled through garbage and/or sewers. Cockroach excrement and cast skins contain a number of allergens to which many people have allergic responses, such as skin rashes, watery eyes, and sneezing. People with asthma may have a severe negative reaction to their feces and body parts. Cockroach infestations may cause human psychological stress and the stigma associated with infestations alters human behaviour.
Cockroaches also carry disease-causing organisms such as bacteria, protozoa, and viruses. Different forms of gastroenteritis, such as food poisoning, dysentery, diarrhea, and other illnesses, are the principal diseases transmitted by German cockroaches.
How can I get rid of cockroaches?
Intensive sanitation and careful application of insecticides should be used jointly to control cockroaches. Some tips:
Survey and Inspection
Placing traps, including sticky traps, at strategic locations allows you to monitor the population and “hot spots” of pest so that you know where to concentrate your efforts.
Sanitation and Exclusion
Regularly clean dark and/or humid areas close to a food source (beneath and behind appliances, stoves, and refrigerators). Keep food in tightly sealed plastic or glass containers. Store garbage in sealed plastic containers and dispose of regularly. Do not allow dirty dishes to accumulate, especially overnight. Vacuum regularly to help remove food particles and insect eggs. Seal and caulk all cracks, crevices and pipe openings to reduce cockroach-hiding places.
Baiting is an effective method to control German cockroaches. Baits containing boric acid, abamectin, or hydramethylnon can provide effective control when applied to the areas where cockroaches harbour.
Dusts like diatomaceous earth, boric acid, or silica aerogel can be used for treatment of cracks and crevices. As the insects crawl over the fine powder, their outer protection is scratched, causing them to slowly dehydrate and die.
The use of residual insecticidal sprays or aerosol foggers is of little value in controlling cockroaches, as these applications may disperse the insects making control more difficult.
For current chemical control options, consult your local pest control representative. Do not apply insecticides in a manner that allows direct contact with food, food-preparation surfaces, or food utensils.
Rana Sarfraz is an entomologist currently working at the University of British Columbia.