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Got bed bugs? Take steps to prevent infestation
Wednesday, July 22, 2009

The human bed bug, bat bug and related species of the family Cimicidae, are blood sucking insects that feed on birds and/or mammals. Five of the cimicid bugs are present in Colorado. If you’ve got bites and have been itching, these bugs may be the culprit.

Bed bug (Cimex lectularius). The bed bug is a notorious species and is the only member of this insect family in Colorado that is adapted to living entirely with humans. For several decades following World War II it was largely eradicated form the United States, existing in only small pockets. However, within the past decade it has had tremendous resurgence. Bed bugs can be accidentally carried on furniture, luggage and other materials so problems with bed bugs tend to be most severe in apartments, motels and other sites that see high amounts of human traffic.

Bat bug (Cimex pilosellus). Prior to the recent increase of bed bugs, the bat bug was the most common representative of this group of insects found within homes in Colorado. Bat bugs develop in colonies of roosting bats, which sometimes occur in attics or behind walls of buildings. Bat bugs may move into human living areas and incidentally bite people, with such migrations particularly common when bats migrate or are eliminated from the building. However, in the absence of the bat hosts, these insects cannot sustain and reproduce.

Swallow bug (Oeciacus vicarius). The swallow bug is a parasite of cliff swallows and, less commonly, barn swallows. Problems with human bites occur in homes where swallows attached and maintained nests during the previous summer. Swallow bug bites of humans tend to occur in late winter and spring, when the swallow bugs emerge from winter dormancy in anticipation of the return of their swallow hosts. The insects are largely dormant during the period between the time nests are abandoned in summer and just prior to the return of swallows the following spring.

Poultry bug (Haematosiphon inodorus). Poultry bugs are associated with chickens and other poultry. They hide during the day in cracks and crevices around the poultry roost and move out to feed at night. Human bites are rare and occur when people spend night activities in close proximity to poultry roosting areas.

Hesperocimex coloradensis. Purple martins and, less commonly, woodpeckers and owls are hosts for H. coloradensis. This species is present in the southwestern areas of the state. Encounters with humans occur when bird hosts nest in buildings.

All of these species are generally similar in appearance. They are reddish-brown to grayish-brown with an oval body form and about 3/8-inch long when full-grown. All are wingless, although small wing pads are present on the back. Their body is flattened when unfed, although they swell rapidly with a blood meal.

Bites

Bed bugs usually feed in the middle of the night while people sleep and the bite is painless. They feed for less than 10 minutes and return to a hiding area to digest the meal. Although the bite is not immediately felt, people often react to the proteins of the bed bug saliva introduced during biting. Typically, a reddish swelling may develop, associated with some itching. There may be little response following the bite with peak itchiness being noticed at about a week, then declining. Repeated exposure to bed bug bites may produce more intensive reactions and itchiness. However, these reactions are highly variable and some people show little response while others react strongly. Regardless of the symptom that develops, there is nothing unique about bed bug bites that can be used for positive diagnosis. The detected presence of bed bugs is needed to determine if a reddish “bite” might be from bed bugs.

History and habits

Female bed bugs cement their small, oval eggs in batches of about two to five eggs. Typical sites for egg laying might be along folds in the mattress, at joints of a bed frame, and behind molding. Ultimately a female may produce over 200 eggs during her months-long adult life span. Eggs hatch in six to 10 days, depending on temperature, and the newly hatched nymphs will immediately seek out food if it is available. Feeding occurs in dark, usually in the middle of the night, and bed bugs use carbon dioxide and heat to locate their host. A blood meal must be taken prior to each molt of the developing bed bug nymph. Blood meals are also required for production of each batch of eggs by the female.

Under optimum conditions, bed bugs can become full-grown in about a month and a half and adults typically may live for about nine months. Cooler temperatures retard development and overall bed bug activity begins to decline with temperatures below about 60 F. However, bed bugs are quite resistant to starvation and adults have been known to survive a year without feeding. Nymphs can tolerate starvation for about three months. When food is available, bed bugs can continue to develop and reproduce year round, producing three or four generations annually.

Within a home bed, bugs are concentrated in the near vicinity of the bed. Most will be found on the frame or mattress, as well as night stands and among other crevices that exist next to the bed. Migrations to adjacent rooms can occur as bed bugs follow holes through walls, such as those produced for electrical wiring and plumbing. Crevices of trim around the walls can be hiding areas as can folds of drapery and areas where drapes rest on the floor. Bed bugs may also settle behind pictures and wall hangings near sleeping areas. Cracks in walls will also be used by bed bugs and can be means by which they can move to other rooms, a particular problem in multi-unit apartments and motels. Electrical outlets often are incompletely sealed and provide points where bed bugs can hide and move behind walls.

Handling bedding

Bed bug treatments in homes often involve intensive prep work by the homeowner. This includes heat treating and bagging up items in the infested area - items that cannot be treated with chemicals. Sheets and other bedding can be easily disinfested by laundering that involves a dryer cycle. The high temperatures involved in drying are critical to successfully kill bed bugs, with exposure to temperatures exceeding 120 F for a few minutes usually sufficient to kill all life stages. Washing, cool drying and dry cleaning may not kill all stages.

Disposal of Infested Items

Disposal may be considered for mattresses, box springs, couches or other furniture that is infested with bed bugs. If this is done, proper disposal should be ensured. Leaving such items on the street for disposal may cause them to be scavenged, which will spread infestations to new dwellings. Be careful when removing the items from the structure so that bed bugs will not become dislodged and infest other areas inside.

Insecticides

Eradication of bed bugs in a home involves use of effective insecticides applied to all points where bed bugs are present. These treatments must directly contact the bed bugs during application. Available insecticides also do not effectively kill egg stages of bed bugs. There is little residual activity of currently available insecticides. Repeated insecticide applications will always be required to kill bed bugs that later hatch from eggs, along with those that were missed during earlier treatment. Currently, available insecticides used for bed bug control are primarily of the pyrethroid class of pesticides. These include bifenthrin, lambda-cyhalothrin, deltamethrin, and beta-cyfluthrin.

Aerosol “bombs” (containing pyrethrins or permethrin) and sprays of non-persisting insecticides (such as pyrethrins or tetramethrin) will not be effective for bed bug control. At most these can be expected to kill a few of the insects that are directly contacted with sufficient quantity of the insecticide. However, they will fail to adequately penetrate hiding sites of many bed bugs resulting in failure of eradication.

Vacuuming

The use of a sealed vacuum during bed bug treatments is useful. Models with strong suction and a directed nozzle can be used to help extract some bed bugs hiding in protected crevices. Vacuums can also be useful for picking up individuals when seen and a general vacuuming of floors and other surfaces may pick up bed bugs that have migrated or been dislodged during bed bug treatments. The addition into the vacuum bag of a drying agent, such as diatomaceous earth, can be useful to kill collected insects. Immediately after use, vacuum bags should be removed, sealed in plastic, and discarded to reduce chances of accidentally spreading bed bugs.

Bed isolation

Isolation of beds can be done to determine if bed bugs are present and, after control efforts have been completed, to ensure that the bug infestation has been eradicated. With bed isolation the box spring and mattress are encased and the frame is treated to insure no bed bugs are present. Then, the four posts that touch the ground are placed onto sticky traps. The homeowner then sleeps in the bed making sure to not let sheets or other bedding to touch the ground. Bed bugs that are in the room will come to feed and get caught in the sticky traps. A period of two or more weeks where no bed bugs are captured on the sticky traps at the base of bed legs is a good indication that the insects have been eliminated from the room.

For more information concerning bed bugs, bat bugs or swallow bugs, contact the Extension Office at 264-5931, or get the facts online at www.archuleta.colostate.edu.