IDENTIFICATION AND LIFE CYCLE
Adult bed bugs are oval, wingless, about 1/5 inch long, and rusty red or mahogany. Their bodies are flattened, they have well-developed antennae, their compound eyes are small, and the area behind the head (the prothorax) expands forward on either side of the head. The immature s appear identical to the adults except for their smaller size, thinner outer skeleton (cuticle), and lighter, yellowish-white color.
Bed bugs are readily distinguished from another common blood-sucking species, conenose bugs by their smaller size, more rounded shape, and lack of wings as adults. Conenose, or kissing, bugs may be up to 3/4 inch long.
Female bed bugs lay 200 to 500 tiny, white eggs in batches of 10 to 50 on rough surfaces such as wood or paper. Glue-like material covers the eggs, which hatch in about 10 days. After hatching occurs, the eggshells frequently remain stuck in place.
There are five progressively larger nymphal stages, each requiring a single blood meal before molting to the next stage. The entire life cycle from egg to adult requires anywhere from 5 weeks to 4 months, depending on temperature and availability of food (blood). When temperatures are in the range of 20° to 25°F, development occurs most rapidly.
Nymphs and adults generally feed at night and hide in crevices during the day. Common hiding places include seams in mattresses and box springs, cracks in bed frames, under loose wallpaper, behind picture frames, and inside furniture and upholstery. Occasionally people pick up bed bugs in theaters or on buses and trains. They also can bring them into their home on clothing, bedding, luggage, or firewood.
Bed bugs can go without feeding for 80 to 140 days. Older stages of nymphs can survive longer without feeding than younger ones, and adults have survived without food for as long as 550 days. A bed bug can take six times its weight in blood, and feeding can take 3 to 10 minutes. Adults live about 10 months, and there can be up to 3 to 4 generations of bed bugs per year.
Bed bugs feed on humans, usually at night when they are asleep. They feed by piercing the skin with their elongated mouth parts, which consist of two stylets that normally fold under their body when at rest but fully extend during blood-meal feeding. One stylet has a groove that carries saliva into the wound, while the other has a groove through which body fluids from the host are taken in.
A single feeding may take up to 10 minutes, and feels like a pin prick, but because feeding usually occurs at night when people are asleep they are not aware they have been bitten until afterwards. However, saliva injected during the feeding can later produce large swellings on the skin that itch and may become irritated and infected when scratched. Swelling may not develop until a day or more after feeding, and some people do not show symptoms. Bed bugs currently are not considered to be disease carriers.
Distinguishing bed bug bites from the bites of other arthropods such as mosquitoes, fleas, and spiders is difficult. People often confuse itching bed bug welts for mosquito bites. The only way you really can confirm bed bugs are the cause is to find the bugs in your bed or bedroom. Often people are bitten when traveling, making diagnosis even more difficult.
In addition to the direct injury to humans, bed bugs have stink glands that leave odors. They also leave unsightly fecal spots on bed sheets and around their hiding places. These spots are darkish red in color, roughly round, and can be very small.
Managing a bed bug infestation is a difficult task that requires removal or treatment of all infested material and follow-up monitoring to ensure the infestation has been eliminated and does not return. Management will require employing several non-chemical methods such as vacuuming, washing bedding at a high temperature, using steam or heat treatment, and sealing up hiding places.
Insecticides may be required to eliminate serious infestations; however few active ingredients are federally registered for bed bugs for over-the-counter use. At the professional control level, there are more registered products; however, resistance among bed bug populations is common, and low-level infestations are difficult to detect. There has been some success combining chemical and non-chemical products with increased sanitation and habitat modification.
Monitoring and Detection.
You can detect a bed bug infestation by searching for the pests or their fecal spots, egg cases, and shed skins (exuviae). Current research reports more than 85% of bed bugs are found in or near the bed, so inspections for infestations should focus on the mattress, bed frame, and headboard areas. Lift the mattress and inspect all seams and surfaces as well as the box springs. You may need to dismantle the bed. Use a flashlight to aid the inspection process.
Remember, these nocturnal insects are small. Although you can see adults and aggregations of nymphs with the unaided eye, seeing the eggs requires a hand-magnifying lens. It may be easier to detect dark spots of dried bed bug excrement or the insects’ light-colored shed skins. A foul, rotting, bloody-meat smell might be present in heavily infested areas.
In addition to the bed area, the remaining 15% of infestations usually are in upholstered furniture other than beds, in bedroom cabinets, along baseboards, under wallpaper, and in carpets, wall hangings and similar hiding spots. Bed bugs prefer fabric or wood surfaces to metal or plastic. For heavy infestations, adjoining rooms, filing areas, and clutter can be out-of-way shelters. It takes patience and perseverance to find low-level infestations of such a persistent, nagging problem.
Recent research has shown searching with dogs can be an effective method for finding bed bug infestations. Under laboratory and simulated-field conditions, using dogs to search for bed bugs was 97% effective. Other recent research indicates using small, double-cupped monitors that are easily installed on the leg ends of beds trapped six times … Continue reading the story "Bed Bugs"