Bedbugs (Cimex lectularius, Cimex hemipterus)
Cimex lectularius has a wide distribution, while C. hemipterus is primarily tropical. Bedbugs measure about 5 mm long by 3 mm wide, are mahogany brown, and have only vestigial wings. The adult bugs may resemble unengorged ticks or very small cockroaches. Although they can mechanically transmit pathogenic microorganisms, there is no conclusive evidence that they are natural biological vectors for the transmission of organisms causing diseases.
Medical problems associated with these bugs include itching and inflammation caused by their bites. Bedbugs are nocturnal and reach their peak activity before dawn; they tend to hide in cracks during the day. They respond to warmth and carbon dioxide in their search for hosts and will respond to a body that is 2°C or more above ambient temperature. They produce an aggregation pheromone that brings them together. Both sexes of nymphs and adults take blood meals, and blood is the sole food of these bugs. The nocturnal biting of bedbugs can be debilitating to humans, whose sleep is interrupted every night.
The presence of the bugs can be suspected by finding their specks of feces and their odor. Bedbugs are very common in Third World countries and are becoming more common even in the United States. Travelers may import bugs in their suitcases or belongings, and the bugs then “make themselves at home” in cracks and crevices, behind baseboards, and under mattresses.
Left, bedbug, Cimex lectularius; Right, Bedbugs (Courtesy of Whitney Cranshaw, Colorado State University)
Left and Right, Skin lesions from bedbugs (Courtesy of Whitney Cranshaw, Colorado State University)