Sometimes referred to as “red coats,” “chinches,” or “mahogany flats”, bed bugs, Cimex lectularius Linnaeus, are blood feeding parasites of humans, chickens, bats and occasionally domesticated animals. Bed bugs are suspected carriers of leprosy, oriental sore, Q-fever, and brucellosis but have never been implicated in the spread of disease to humans. After the development and use of modern insecticides, such as DDT, bed bug infestations have virtually disappeared. However, since 1995, pest management professionals have noticed an increase in bed bug related complaints.
Human dwellings, birds nests, and bat caves make the most suitable habitats for bed bugs since they offer warmth, areas to hide, and most importantly hosts on which to feed. Bed bugs are not evenly distributed throughout the environment but are instead concentrated in harborages. Within human dwellings, harborages include cracks and crevices in walls, furniture, behind wallpaper and wood paneling, or under carpeting. Bed bugs are usually only active during night but will feed during the day when hungry. Bed bugs can be transported on clothing, in traveler’s luggage, or in bedding and furniture but lack appendages to enable them to cling to hair, fur, or feathers, so are rarely found on hosts.
The adult bed bug is a broadly flattened, ovoid, insect with greatly reduced wings. The reduced fore wings, or hemelytra, are broader than they are long, with a somewhat rectangular appearance. The sides of the pronotum are covered with short, stiff hairs. Before feeding, bed bugs are usually brown in color and range from 6 to 9.5 mm in length. After feeding, the body is often swollen and red in color. The two bed bugs most important to man are the common bed bug, Cimex lectularius, and the tropical bed bug, Cimex hemipterus. These two species of bed bugs can easily be distinguished by looking at the prothorax, the first segment of the thorax. The prothorax of the common bed bug is more expanded laterally and the extreme margins are more flattened than that of the tropical bed bug.
Because of their confined living spaces, copulation among male and female bed bugs is difficult. The female possesses a secondary copulatory aperture, Ribaga’s organ or paragenital sinus, on the fourth abdominal sternum where spermatozoa from the male are injected. The spermatozoa then migrate to the ovaries by passing through the haemocoel, or body cavity. The female bed bug lays approximately 200 eggs during her life span at a rate of one to 12 eggs per day. The eggs are laid on rough surfaces and coated with a transparent cement to adhere them to the substrate. Within six to 17 days bed bug nymphs, almost devoid of color, emerge from the eggs. After five molts, which takes approximately ten weeks, the nymphs reach maturity.
Survey and Management
Bed bugs are most active at night, they are extremely shy and wary so their infestations are not easily located. However, when bed bugs are numerous, a foul odor from oily secretions can easily be detected. Other recognizable signs of a bed bug infestation include excrement left around points of entry and exit to their hiding places and reddish brown spots on mattresses and furniture. Good sanitation is the first step to controlling the spread of bed bugs. However, upscale hotels and private homes have recently noted infestations, suggesting that good sanitation is not enough to stop a bed bug infestation. If bed bugs are located in bedding material or mattresses, control should focus on mechanical methods of control, such as vacuuming, caulking and removing or sealing loose wallpaper, to minimize the use of pesticides. The effectiveness of using steam cleaners or hot water to clean mattresses is questionable. Heat is readily absorbed by the mattress and does no harm to the bed bug in fact the moisture may produce favorable conditions for house dust mites. Pillows should be removed and dry-cleaned or replaced. For severe infestations, however, pesticides may be used. If pesticides are used, allow bedding and furniture to dry throughly before using.