Bed Bugs

Bed bugs are parasites that preferentially feed on humans. They were common in the United States prior to World War II, after which time widespread use of synthetic insecticides such as DDT greatly reduced their numbers. Improvements in household and personal cleanliness as well as increased regulation of the used furniture market also likely contributed to their reduced pest status.

In the past decade, bed bugs have begun making a comeback across the United States. . The widespread use of baits rather than insecticide sprays for ant and cockroach control is a factor that has been implicated in their return. Bed bugs are blood feeders that do not feed on ant and cockroach baits. International travel and commerce are thought to facilitate the spread of these insect hitchhikers. Bed bugs are most frequently found in dwellings with a high rate of occupant turnover, such as hotels, motels, hostels, dormitories, shelters, apartment complexes, tenements, and prisons. Such infestations usually are not a reflection of poor hygiene or bad housekeeping.

Bed bugs do not generally travel too far from their host. But when hiding places and hosts are few, they may be found almost anywhere – in mattress seams, in bed springs, in floorboard cracks, behind peeled wallpaper, in picture frames, in couches and stuffed chairs, on clothing, and even in the seams of curtains.

Identification, Biology, and Habits

Adults are brown, flat and about a 1/4-inch long, with a soft, rounded look. After a blood meal they are dark red, rounded (distended), and about 3/8-inch long. These pests usually come out at night or in darkened areas. The small white eggs hatch into almost transparent nymphs that start feeding at the first opportunity and molt five times before becoming adults. Usually, all stages of development are present in an infestation. A temperature of 70°F is ideal for bed bugs; only adults are present at 50°F or lower. Bed bugs have been known to live as long as 18 months. At least three generations per year are possible.

Bed bugs are fast moving and usually feed at night, but very hungry bed bugs are less likely to wait for darkness. After using their sharp beak to pierce the skin of a host, they inject a salivary fluid containing an anticoagulant to help them get their blood meal. In spite of their feeding habits, bed bugs are not known to carry diseases. 

Injury

The bite is painless. The salivary fluid typically causes the skin to become irritated and inflamed, although individuals can differ in their sensitivity. A small, hard, swollen, white welt may develop at the site of each bite and is accompanied by severe itching that lasts for several hours to days. Scratching may cause the welts to become infected. Rows of three or so welts on exposed skin are characteristic signs of bed bugs. Welts do not have a red spot in the center such as is characteristic of flea bites.

Control Measures

A critical first step is to correctly identify the blood-feeding pest, as this determines which management tactics to adopt. A bed bug infestation can be recognized by blood stains from crushed bugs or by rusty (sometimes dark) spots of excrement on sheets and mattresses, bed clothes, and walls. Fecal spots, eggshells, and shed skins  may be found in the vicinity of their hiding places. An offensive, sweet, musty odor from their scent glands may be detected when bed bug infestations are severe. 

Control of bed bugs can be difficult and is best achieved by following an integrated pest management (IPM) approach that involves multiple tactics, such as preventive measures, sanitation, and chemicals applied to targeted sites. Following are steps that may be taken as control measures:

1. Do not bring infested items into the house: carefully inspect clothing and baggage of travelers and inspect secondhand beds, bedding, and furniture. Caulk cracks and crevices in the building exterior and also repair or screen openings.

2. A thorough inspection of the premises should concentrate on the mattress, box springs, and bed frame, as well as crack and crevices that the bed bugs may hide in during the day or when digesting a blood meal. The latter sites include window and door frames, floor cracks, carpet tack boards, baseboards, electrical boxes, appliances, furniture, TVs, picture frames, wall hangings, drapery pleats, loosened wallpaper, cracks in plaster, and ceiling moldings.

3. Sanitation measures include frequently vacuuming the mattress and premises, laundering bedding and clothing in hot water, and cleaning and sanitizing dwellings. After vacuuming, immediately place the vacuum cleaner bag in a plastic bag, seal tightly, and discard. Repair cracks in plaster and glue down loosened wallpaper to eliminate bed bug harborage sites.

4. After the mattress and pillows are vacuumed or scrubbed or steam cleaned, they can be enclosed in zippered covers. (Stuffed toys and pillows can also be put in the dryer for ten minutes at High setting.) Any bed bugs remaining will be trapped inside the cover. Leave the cover in place for a year.

5. Heavily infested items should be destroyed or discarded. Don’t leave upholstered furniture for others to pick up – tear open the upholstery and dismantle the structure. 

6. Sticky traps or glueboards may be used to capture bed bugs that wander about. However, the effectiveness of these traps is not well documented.

7. Apply residual insecticides (usually pyrethroids) to cracks and crevices. Repeat the applications if you see signs of bugs again after two weeks.

Do not use any insecticide on a mattress unless the product label specifically mentions such use. Allow the treated surface to completely dry before use. Do not sleep directly on a treated mattress; be sure bed linens are in place. Do not treat mattresses of infants or ill people.

 If your efforts to control bed bugs fail contact a pest control operator (exterminator.)

Sources: Pest Management Office, University of Maine Cooperative Extension; Susan C. Jones, Ph.D., Assistant Professor of Entomology and Ohio State University Extension

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