Bed bugs outlasted mid-century eradication and can starve for months
Night-feeding Cimex bugs leave itchy welts without proven disease transmission. Egyptian fossils show they have parasitized humans for at least 3,500 years. After near wipeout in rich countries following World War II, infestations roared back—and adults may survive roughly 300 days without a meal.
Two species do nearly all the biting: the common bed bug, Cimex lectularius, and the tropical Cimex hemipterus. Adults are flat, oval, reddish-brown and 4 to 5 millimetres long, with front wings shrunk to pads and no hind wings at all. They pass through five nymph stages, each needing at least one blood meal before the insect can moult. How long they can fast is reported differently: one figure says around 70 days at any life stage, another up to roughly 300 days, which helps explain why homes are so hard to clear.
Carbon dioxide draws them first, then warmth and body odours. Their mouthparts saw into skin and inject saliva laced with anticoagulant and painkiller, so the bite often goes unnoticed; the common species feeds only every five to seven days and spends the rest of its time packed with eggs and young in cracks near beds, luggage or even electrical sockets. A heavy infestation smells sweet and pungent, likened to rotting raspberries, and trained dogs find them with accuracy reported anywhere from 11 to 83 percent.
Reactions range from nothing, in about a fifth of people, to itchy red welts a few millimetres across, sometimes in lines, and rarely to anaphylaxis; heavy, chronic feeding can cause anaemia, and the stress can bring sleeplessness or even an obsessive delusion of infestation. There is no evidence they spread infectious disease. Symptoms usually fade on their own within one to two weeks. Eradication may take repeated rounds of heating rooms to 50 degrees Celsius for over 90 minutes, hot laundry, vacuuming, pesticides and diatomaceous earth.
Poor hygiene is rarely the cause. The bugs hitch rides in clothing, bags and second-hand furniture, travel through ducts, and increasingly turn up on flights. Pets can be bitten but do not carry them. Nearly wiped out in wealthy countries after the Second World War, bed bugs have surged since the 1990s.
Source: Bed bug
