bed bug biology

BED BUG BIOLOGY

Biology

Adult bedbugs are reddish-brown, flattened, oval, and wingless. Bedbugs have microscopic hairs that give them a banded appearance. A common misconception is that they are not visible to the naked eye. Adults grow to 4–5 mm in length and 1.5-3 mm wide. They do not move quickly enough to escape the notice of an observer. Newly hatched nymphs are translucent, lighter in color and become browner as they moult and reach maturity. Bedbugs are true insects and are not arachnids, unlike dust mites and ticks.

Feeding Habits

Bedbugs are bloodsucking insects. They are normally active at night just before dawn, with a peak feeding period of about an hour before sunrise. Bedbugs may attempt to feed at other times if given the opportunity and have been observed feeding during all periods of the day. They reach their host by walking, or sometimes climb the walls to the ceiling and drop down on feeling a heat wave. Bedbugs are attracted to their hosts by warmth and the presence of carbon dioxide. The bug pierces the skin of its host with two hollow feeding tubes. With one tube it injects its saliva, which contains anticoagulants and anesthetics, while with the other it withdraws the blood of its host. After feeding for about five minutes, the bug returns to its hiding place. The bites cannot usually be felt until some minutes or hours later, as a dermatological reaction to the injected agents, and the first indication of a bite usually comes from the desire to scratch the bite site. Because of their natural aversion for sunlight, bedbugs normally come out at night.

Although bedbugs can live for a year or eighteen months without feeding, they normally try to feed every five to ten days. Bedbugs that go dormant for lack of food often live longer than a year, while well-fed specimens typically live six to nine months.

Low infestations may be difficult to detect and in the early stages, victims may not realize they have bedbugs. Patterns of bites in a row or a cluster are typical, as the insects may be disturbed while feeding. Bites may be found in a variety of places on the body.

Bites

Most observed bites consist of a raised red bump or flat welt, and are often accompanied by very intense itching. The red mark is the result of an allergic reaction to the anesthetic contained in the bedbug's saliva, which is inserted into the blood of its victim. Reactions to bedbug bites may appear indistinguishable from mosquito bites although they tend to last for longer periods. Bites may not become immediately visible and can take up to nine days to appear.

Disease transmission

Bedbugs seem to possess all of the necessary prerequisites for being capable of passing diseases from one host to another, but there have been no known cases of bed bugs passing disease from host to host. There are at least twenty-seven known pathogens (some estimates are as high as forty-one) that are capable of living inside a bed bug or on its mouthparts. Extensive testing in laboratory settings concludes that bed bugs are unlikely to pass disease from one person to another. Therefore bedbugs are less dangerous than some more common insects such as the flea.

Infestations

There are several ways in which dwellings can become infested with bedbugs. One common way is for them to be picked up while traveling or when staying at temporary lodging such as hotels, bed-and-breakfasts, hostels, or motels -- which are places that have been traditionally associated with an increased risk for housing bedbugs due to their higher rate of turnover and continual influx of temporary residents. Once acquired at such travel locations, the now hitchhiking bedbugs may then be transported and brought back to the homes of the guests in their luggage where a new infestation can then take place inside the home.

Bedbugs can also be picked up inadvertently through bringing infested furniture or contaminated, used clothing into a household. Though such furniture does not necessarily have to have been previously owned or discarded -- as even brand new furniture can be exposed to bedbugs during storage or in delivery vehicles. Nor do the used clothes have to be clothing that had been previously obtained through borrowing, secondhand purchase or through donation — since any exposed and unwashed apparel is capable of transferring bedbugs. Toys such as stuffed dolls or other bedroom items can be infested as well.

Bedbugs may also introduce themselves into a new residence by traveling between multi-unit housing such as condominiums, dormitories, and apartment buildings, or arrive after having exited infested furniture that has been thrown out, discarded and/or placed outside for garbage collection or for treatment. This unintentional spread between adjacent homesites and nearby units is dependent, in part, upon the degree of infestation at the source (i.e. a heavier infestation is more likely to spread), but also upon the building material used to partition units and the material used to seal connecting pipes, vents, wires, etc. Further potential to spread is also directly related to the manner in which infested items are disposed of — such as whether or not contaminated furniture is dragged through common areas while being removed, which can result in the shedding of bedbugs or their eggs while being dragged — and whether or not infested items have been properly sealed once discarded. Bedbugs can also be transmitted via animal vectors including wild birds and household pets.

In places that are severely infested, bedbugs may actually crawl onto a person's clothes and be carried from location to location allowing the bugs to spread in this manner -- though, it should be noted, that this sort of hitchhiking behavior is typically associated only with severe cases or with cases of heavy infestations that are poorly managed. It is also common for bedbugs to nest in clothing articles that are generally not washed often (i.e. living and nesting inside of jackets, coats, purses, shoes, etc.) and for them to then spread when such apparel is either stored publicly with other apparel (as in locker rooms and on coat racks) or to spread when the unwashed, contaminated clothing comes into direct contact with high-trafficked public surfaces. Otherwise, bedbugs will not be usually carried from place to place by people on the clothing they are currently wearing. General machine washing and drying on high heat will disinfect most clothing of potential bedbugs and will kill their eggs as well.

The transmission of bedbug eggs is also an issue. It is not uncommon for the live bedbugs amongst an infestation to be completely eradicated during an effective treatment cycle only to have the remaining or surviving eggs hatch and reinfest the location. The bedbug eggs themselves are usually unaffected by and/or not killed by most approved pesticides. The eggs can also have an incubation period of up to several weeks and may be deposited in hidden areas that are difficult to penetrate, difficult to find, or simply hidden away from what otherwise would have been a quick lethal treatment. This stubborn tendency of bedbug infestations towards reemergence can be incredibly problematic and made all the more difficult to detect due to a now smaller size of the newly re-emerged bedbug nymphs.

Nesting Locations

Bedbugs travel easily and quickly along pipes and boards, and their bodies are very flat, which allows them to hide in tiny crevices. In the daytime, they tend to stay out of the light, preferring to remain hidden in such places as mattress seams, mattress interiors, bed frames, nearby furniture, carpeting, baseboards, inner walls, tiny wood holes, and/or room clutter. Bedbugs can be found on their own but will more often congregate in groups once established. They tend not to travel further than 100 feet (30 m) from their host to feed and will usually remain close to their blood supply in the same bedroom or living quarters where people sleep.

If children are in the house, bedbugs may also hide in toys and other recreational objects or in areas where younger ones play and/or nap. Bedbugs have also been found in door hinges, electrical fittings, in fire alarms, in lighting fixtures, amongst windowsills, in the cracks of plaster, behind peeled wallpaper, around curtains, in the cracks of brick and mortar, inside electronic devices, in various furniture, in floor cracks. And in blankets, purses, suitcases, lamp shades, inside speakers, under lamps, in vents, in shoes, above doorways and windows, under appliances, underneath linoleum, in storage, in books, in scattered paper, in envelopes, behind wiring, along piping (including both gas and plumbing pipes), in velcro, inside hollow doors, in ceiling fixtures, above the bed, in toys, in the ceiling, in phones, etc. -- put simply, it is possible that bedbugs may nest into any cracks or crevices that lie nearest to their hosts. Also, wicker furniture is known to be particularly targeted by bedbugs as a preferred nesting haven and should be removed in suspected areas.

The information below is from the "Wikipedia" listing on bed bugs:

Bed bugs (Cimex lectularius) are small, elusive, and parasitic insects of the family Cimicidae. They live strictly by feeding on the blood of humans and other warm-blooded animals. The name 'bed bug' is derived from the insect's preferred habitat infesting houses and especially beds or other common areas where people may sleep. Bedbugs, though not strictly nocturnal, are mainly active at night and are capable of feeding unnoticed on their hosts.