Introduction
This bug probably received its common name of bed bug from its close association with human sleeping beds where it often seeks refuge during daylight, only to come out to feed on the bed’s occupant(s) at night; they have been called by over 50 common names that include red coats, mahogany flats, and wall-lice, to name a few. The bed bug is an ectoparasite of primarily humans but will also attack poultry and other mammals and birds. It was introduced into the United States with the early colonists. It is found throughout the United States and the temperate regions of the world. Its’ association with humans has been documented to date back more than 3,300 years (1336 BC in Egypt).
In 2004, NPMA estimated a 500% increase in the preceding 3 years. The resurgence of bed bugs that started in the mid-1990s is probably due to a combination of factors such as the 5 that follow.
- Bed bugs are excellent hitch hikers and the United States in 1995 had 43 million international tourists visit, in 1999 the number was 48 million, and in 2000 it was up to 51 million; likewise, millions of Americans annually visit foreign countries.
- The greater use of integrated pest management techniques by pest management profes- sionals where infestations are treated in a targeted manner (e.g., baits for cockroaches) allows insects in untreated areas of the ecosystem to increase.
- Although mostly eliminated in the United States after World War II, bed bugs remained prevalent in Asia, Africa, Central and South America, and Europe where heavy reliance for about the last 15 years on parathyroid pesticides for control measures selected for bed bug resistance and cross-resistance to parathyroids, now found to be from several-hundred to several- thousand fold in some cases; most pesticides presently labeled for bed bugs are pyrethroids.
- The removal from the marketplace of several different classes of pesticides that previously had given very effective control and the removal of bed bugs from most remaining product labels because no need was perceived.
- The unfamiliarity of physicians and the public at large with bed bugs, which allows infestations to increase until the diagnosis/identification is corrected and proper treatment rendered.
Recognition
Adults about 3/16″ (4-5 mm) long; broadly oval and flat. Color brown to reddish brown (after feeding). Head with beak/proboscis 3-segmented, not extending beyond front coxae. Ocelli absent. Antenna 4-segmented, 3rd segment longer than 2nd or 4th. Pronotum with front margin deeply concave to receive head, with side margins greatly expanded forward to beyond eyes, pronotum more than 2.5 times as wide as long at its middle; fringe hairs on pronotum shorter than width of eye. Bases (coxae) of middle and hind legs widely separated; tarsi 3-segmented. Front wings vestigial, reduced to wing pads; with contiguous (touching) portions shorter than scutellum (triangular plate directly behind pronotum) in length. Body upper surface sparsely covered with short golden hairs (setae), usually shorter than diameter of 2nd antennal segment. Emit an “obnoxiously sweet” odor from scent glands.
Nymphs resemble adults but are smaller and paler in color; white just after molting and then light tan in color before feeding.
Similar Groups
- Tropical bed bug (Cimex hemipterus) with pronotum less than 2.5 times as wide as long at its middle; southern Florida.
- Bat bugs (C. adjunctus and C. pilosellus) with upper surface of body covered with long hairs (setae), length 1.5 or more times the diameter of the 2nd antennal segment, fringe hairs on pronotum longer than, or equal to, width of eye.
- Swallow bug (Oeciacus vicarius) with 3rd and 4th antennal segments equal in length.
- Poultry bug (Haematosiphon inodorus) with beak/proboscis extending back to hind coxae.
- Swift bug (Cimexopsis nyctalis) with bases (coxae) of middle and hind legs nearly touching and body bare, lacking hairs.
- (Flat bugs (family Aradidae) with narrow wings, abdomen extending beyond them, beak/probosis 4-segmented, and tarsi 2-segmented.
Biology
Female bed bugs lay 1 -5 eggs per day with the 1/32″ (1 mm) long, white eggs being deposited individually in cracks or on rough surfaces and secured with a transparent cement for an average total of 200 eggs; maximum eggs per day is 12, with 541 for a lifetime. There are 5 nymphal instars with a blood meal required for each molt. About 3-10 minutes are required for each blood meal, during which saliva containing an anticoagulant is injected. Developmental time (egg to adult) takes 21 days at 86°F/30°C to 120 days at 65°F/18°C, with an additional 3 or 8 days respectively for oviposition to occur. The threshold for egg hatching, nymphal development, and adult activity is 55- 59°F/13-15°C. Below 61°F/16°C adults enter semihibernation and the thermal death point is 111-113°F/44-45°C. Without a blood meal, once-fed nymphs can survive an average of 51 days (range 28-73) at 81°F/27°C and 70-75% RH. Being poorly fed can greatly prolong the nymphal period (35-48 days to 158 days in one study). With normal feeding and reproductive cycles, individuals can live up to 316 days.
Humans are the preferred host of bed bugs and they tend to feed on any bare skin that is exposed while sleeping.
Although the bite of bed bugs is painless, many people develop an allergic reaction to the saliva injected by the bug as it feeds. A swelling usually results from feeding but there is no red spot such as is characteristic with flea bites. Swelling may be severe and extend beyond the immediate bite area in highly sensitive individuals. However, some individuals never develop a reaction to bites, and some after long exposure to bites eventually reach a point where they no longer have a reaction to bites.
Bed bugs have been found to be infected with some 25 different disease organisms. Survival time within the bed bug was found to be especially long (147-285 days) for the organisms of plague, relapsing fever, tularermia, and Q fever. However, although bed bugs have been suspect in the transmission of many diseases or disease organisms in humans, conclusive evidence of transmission is lacking. The principal medical concern is limited to the itching and secondary infections from scratching.
Habits
Bed bugs are efficient hitchhikers and easily transported. Once introduced, they are often spread throughout a building. They harbor in cracks and crevices during the day and come out to feed at night. The senior author has experienced hungry bed bugs becoming very active during the day and orientating to his presence when exposed to his normal breathing and body odors while he was taking images of the infestation.
In hotels/motels, the number one place for infestations is the backside of headboards mounted on walls; these must be removed for inspection. Typically, initial infestations of bed bugs are found associated with the bed such as around mattress buttons and beading, in boxsprings or their coverings, and in any crevice of a wooden bed frame, such as where members join. They are particularly fond of wood and fabrics as opposed to plastic and metal.
Eventually, other places are infested including wall hangings such as picture frames and mirrors, night stands, stuffed furniture (especially if used for sleeping), baseboards, floorboard cracks, behind loose wallpaper, light switches, door and window frames, curtains/drapes, under carpets between the tac-strip and baseboard, conduits, etc. Clutter is a bed bug’s best friend and must be eliminated. In heavier infestations, bed bugs may be found in telephones, radios/CD players, clocks, televisions, in items stored under beds, wall voids, electrical outlet boxes, attics, and other enclosed places. In addition, a few bugs and/or eggs can often be found in areas distant from the bed on the other side of the room. They will crawl distances in excess of 100 feet (30 m) to obtain a blood meal. If left untreated, the infestation will spread to adjoining rooms and/or apartments; think/inspect in 3 dimensions.
Because of their hitchhiking abilities, they can be introduced into a structure via used furniture or in the belongings of someone who has been living in or visiting a bed bug infested situation. Adults can survive for up to one year if they are well fed. In the absence of humans, bed bugs will feed on any warm-blooded animal including poultry, canaries, English sparrows, mice, rats, bats, and household pets such as guinea pigs and dogs. When the temperature falls below 61°F/16°C, adults enter semihibernation and can survive for months.
Bed bug infestations have been found in transportation vehicles such as boats, trains, airplanes, and buses as well as in movie theaters where they typically harborage in seats and associated frames.
Presently, most infestations are encountered in hotels/motels (all levels of prestige), youth hostels, shelters, and dormitories, probably because of the transient nature of occupation and student visitation habits in dormitories. In these situations, infestations may become widespread, but customer/resident complaints usually prevent them from becoming very severe before professional help is sought. Apartments and single-family residences are a distant second, but infestations here can build up to tremendous numbers before professional help is sought.
The primary clues to an infestation will be the presence of small red to reddish brown fecal spots clustered on surfaces near harborages, bed bug molt skins, their eggs or empty egg shells, and/or bed bugs themselves. In very heavy infestations, the characteristic obnoxiously sweet bed bug odor may be detected.
Control
A thorough inspection that may take several hours is indispensable; refer to the habits section above for suggestions. Treat any bed bugs found with an appropriately labeled pesticide; in general, aerosols and liquids are best, but dusts are better for under baseboards, the tac-strip area under carpets, and voids including outlet boxes and the inner framework of sofas and stuffed chairs. The proper use of steam has proven to be an effective means of control in certain situations such as mattresses, boxsprings, stuffed furniture, stuffed toys, etc., but depth of penetration can be a problem. Use the large nozzle, 1.5″ from the surface and move slowly.
Great care should be taken when treating mattresses, box springs, and upholstery to keep pesticide exposure to the customer to a minimum; allow for thorough drying before reuse. Infant’s and infirmed person’s bedding and bed frames should not be treated. If the customer is comfortable with the idea, mattresses and box springs can be encased in tight-sealing covers designed for house dust mite prevention or control. Otherwise, they should be replaced with uninfested items.
Infested items including linens and clothes should only be removed from a room once they are encased in a plastic bag to prevent spreading the infestation by bed bugs falling off during transport. A normal hot wash cycle will kill bed bugs. Running dry clothes or other items (non-washables such as backpacks, shoes, etc.) through a hot drier (as hot as the fabrics can withstand, but a minimum of 140ºF/60ºC) for 10 minutes kills all stages, but don’t run larger than half-loads. Wet clothes/loads need to be thoroughly/completely dried first, then run the drier hot (as hot as the fabrics can withstand, but a minimum of 140ºF/60ºC) for 10 minutes. If freezing is appropriate or desirable, hold the items at 27ºF/- 5ºC for 5 days in a non-defrosting kind of freezer. If a bed bug infestation is discovered when it is confined to 1 or 2 places, it can often be controlled with a single application to infested and adjoining areas, and/or by replacing the infested items; follow-up inspections should be scheduled at least monthly to be sure. For established infestations, several services will be required with 2-week intervals being the norm for the first 2 or 3 months depending on the severity of the infestation. In apartment buildings and hotels, it’s highly advisable to also inspect units to either side and above and below the infested unit(s), and treat as required.
In apartments, one study found that the boxsprings were the most heavily infested item (35%), mattresses (22%) and sofas/reclining chairs (23%) were about tied for second, and bedframes/headboards were third (13%). The other 7% were found in items such as inside a coffee maker and books, associated with walls, ceilings, and baseboards, in nightstands and dressers, which were often several feet away from the bed. The time spent was 1-2 man-hours on the initial and at least 1 hour (and often much more) on each follow-up visit. Especially on the initial, 2 people are required to lift, tear apart, and move furniture. In hotels/motels, headboards mounted on walls are usually the place of first infestation. Even though complaints should greatly diminish or stop after a few weeks of service, follow-up inspections are advisable for several months because it is extremely difficult to achieve 100% elimination. Remember, bed bugs are easily reintroduced, especially in communal or rental units/situations.
In cases where the infestation is severe, high pyrethroid resistance is established, when peace-of-mind must be addressed, and/or when quick elimination is required, fumigation should be seriously considered. Fumigation may at first appear to be costly, but when every cost or loss is added up, it may be very cost effective.