Eggs	Eggs	Nymph	Cluster	Adult Male	Adult Female	Feeding	Stains
Engorged	Blood stain	Mouth parts	Feeding on arm	Cast skin	Adult male	Adult female	Bat bug

Infestations of bed bugs are on the increase...

Human bed bugs (Cimex lectularius) are found throughout the world and are significantly increasing in numbers in North America as well as in many other countries.  Even though we do not understand fully all of the reasons behind this increase, we suspect possible contributing factors such as a reduction in the use of urban pesticides, the more extensive world travel of different cultures and resistance to pesticides.  This sudden increase in bed bug infestations has resulted in anxiety among the public, increased negative exposure of the hotel industry and a need to educate public health officials and pest control professionals on safe and effective control measures.

To complicate matters, there is a small group of related blood sucking bugs in the family Cimicidae including bat bugs and swallow bugs that can be confused with human bed bugs.  It is important to identify the species of bed bug because due to their different habits, proper identification determines where to direct controls to be most effective. For example, bat bugs (Cimex pilosellus) look similar to human bed bugs but control efforts must involve elimination of bats from a structure to be effective.

During the last decade, there has been a significant increase in the number of bed bug infestations reported from homes, resort hotels, apartments, universities and cruise ships. Over time, as society becomes more experienced in recognizing bed bug infestations early and professional pest control companies gain expertise in control, bed bug infestations in communities should decline.  This web site is intended to assist you to prevent infestations, understand the identification of bed bugs, recognize the symptoms of bed bug bites, and learn how to get rid of bed bugs if your dwelling becomes infested.

1. How to prevent bed bug infestations

Human bed bugs (Cimex lectularius) are constantly being transported and dispersed in luggage, bedding and other items such as bedroom furniture.  Once transported to a dwelling, bed bugs typically live in cracks and crevices in the bedroom and feed on people during the night time.  Many individuals are worried about bringing bed bugs home during their travels.  Although it is not as easy to transport bed bugs as one might expect, there are special considerations that one should follow to minimize the probability of accidentally introducing bed bugs into your home.

• During travel, before you check into a hotel, check into the mattress.  Carefully remove the sheets and examine the head section of the bed, look at the seams of the mattress as well as both sides of the head board.  If you see any small insects in either of these locations, they are probably bed bugs.

Above: Bed bugs hiding under seam of mattress

• Bringing your favorite pillow along on your travels may increase the chances of this pillow becoming infested with bed bugs and the transport of these bed bugs back to your home.  If you have a favorite pillow, make sure it is encased in a bed bug proof sealed pillow case.
• Remember not to place your luggage next to the bed during travels.  Find a location as far from the head of the bed as possible and store your luggage in this location.  This same principle applies to portable radios and other items that could conceal bed bugs.
• If you do see bed bugs or think you have been bitten by bed bugs during your travel, it is extremely important to report this incident to the hotel management or else other unsuspecting individuals may meet the same fate.
• Do not bring mattresses, bed frames or other bedroom furniture into your home unless you are first confident that bed bugs are not hiding in cracks and crevices.
• If you have visitors that are coming to stay with you, ask them not to bring along personal pillows and bedroom furniture.  If you have any special concerns, ask them first about bed bugs to make sure they don’t accidentally bring them into your home.

If you are bitten by bed bugs during your travels, whether in a hotel, private residence or on public transportation, it is not likely that you will bring these bed bugs home if you follow the steps outlined above.  In many cases the itches from bites are delayed until the next day and you may incorrectly assume that you have transported bed bugs.   Since bed bugs bite at night and hide by day, just entering an infested area during the day is not cause for alarm.

2. Recognizing bed bug bites

Frequently, the first evidence of the presence of bed bugs is the sudden appearance of very itchy bites on your torso.  It is important to seek medical attention if bites alone are the only evidence of bed bugs.  Dermatologists may recognize skin rashes, allergies and other conditions that are not insect bites.

There are several other insects and arthropods that will produce itchy welts very similar to bed bug bites.   This is because mosquitoes, fleas, lice, mites and bed bugs all inject salvia during the feeding process to thin human blood.  This anti-coagulant material is largely responsible for the “itchiness” of bites.  Individuals vary greatly in their skin response to different insect and arthropod saliva and over time some individuals may become either more or less affected.

3. How to identify and collect bed bugs

Even though bed bugs are small, about 1/5 th of an inch, they can be readily seen with the naked eye.  Immature bed bugs are light yellow in color unless they have recently fed on blood and then they are darker in the middle.  After a recent feeding, you can almost see the red color of blood inside. As the blood ages, it darkens and a small quantity of undigested blood is excreted onto surfaces such as bed sheets, mattresses and on other surfaces.  Adults are reddish brown and they also turn darker after a blood meal. They are wingless, oval and flattened in appearance and crawl at a steady rate.

Bed bugs are active at night when they leave their daytime resting place deep inside cracks and crevices to seek out human blood. If bed bugs are seen during the day, it usually means that their hiding location has been disturbed, they have contacted a pesticide, or else they are very hungry and are desperately seeking a blood meal.  Adult male and female bed bugs, as well as nymphs (young), feed on blood. By checking the bed linen in the middle of the night you have the best opportunity to find bed bugs on the move. Bed bug bites are normally two or three in a row and often blood spots are deposited on the sheeting. Any nearby crack or crevice can serve as a daytime refuge for bed bugs. Look for bed bugs under folds in mattresses, along seams and in between bedposts and bed slats. Other places to look for bed bugs during the day include behind baseboards, in night stands, inside pillow cases and inside any piece of furniture that is located adjacent to the bed. When large numbers of bed bugs are present, they produce a distinctive pungent odor. Numerous dark fecal spots on linen or near cracks are another indication of a bed bug infestation.  If only one or two bed bugs are found, it is difficult to estimate how many other bed bugs are in hiding.  Large infestations of bed bugs have a tendency to disperse to other locations in the building, especially if the host person vacates their room for a period of time.

There are no simple traps available that this author is aware of that will reliably trap bed bugs.  Conventional sticky traps for common insects that crawl inside rooms are usually only effective if the bed bug infestation is very large.  Not only are very light infestations of bed bugs difficult to recognize, but the elimination of all bed bugs in a room is equally difficult to measure.  The lack of bed bug bites is often the best tool we have to show that control efforts have succeeded.

Bed bugs should be collected into small leak-proof containers of rubbing or other alcohol. Clear sticky tape is also a good way to capture individuals for later identification.  Bed bug specimens should be sent to a knowledgeable expert for positive identification. There are many other small insects that could be mistaken for bed bugs and experience shows that only a small percentage of specimens sent in for identification are actually bed bugs.  Dr. Richard Pollack at the Harvard School of Public Health can identify bed bugs sent in from Harvard University. Take a look at the Bed Bug Training Slides at the beginning of this web page for a series of photographs of different stages of bed bugs and bed bug evidence.  There is also the image gallery at the top of this page to give you an idea of the diversity of bed bug images.

4. Bed bug biology and behavior

After feeding, a female bed bug will lay eggs in their daytime refuge of cracks and crevices.  Each egg is whitish in color and flask-shaped.  These eggs are visible to the human eye and can be found close to the hiding places of immature bed bugs, under seams of mattresses and in other similar places. An immature bed bug may take several months to mature to an adult and an adult bed bug can live for up to one year. During development, the young bed bug will feed frequently on the blood of humans and they can exist for many months between blood meals. This means it is not practical to starve bed bugs by staying away for short periods of time, instead this activity may serve to spread bed bugs more quickly in a facility.

Bed bug eggs	Bed bug nymph

Bed bugs inject saliva into the blood stream of their host to thin the blood and to prevent coagulation. It is this saliva that causes the intense itching and welts. The delay in the onset of itching gives the feeding bed bug time to escape into cracks and crevices. In some cases, the itchy bites can develop into painful welts that last several days. The good news is that this insect is not known to transmit human disease.  There is considerable individual variation in the response to bed bug bites.  Some individuals may respond less to the bites over time while others may increase in their reaction to bed bug bites.  This makes it difficult to identify the exact date when bed bugs first appear since bites are usually the first clue that bed bugs are present.

Spiders, fleas, mites, ticks, mosquitoes or even lice can also cause itchy bites, and these pests require different control methods.  There may also be cases where what appears to be a bed bug or other insect bite is not caused by bed bugs or other pests at all.  Until a bed bug is positively identified by a knowledgeable expert, it is not recommended to treat a dwelling for bed bugs.  The addition of pesticides in the sleeping rooms of individuals is a serious matter and should not be taken lightly.

5. How to control bed bugs

The first step in control is to eliminate the possibility of bed bugs physically climbing over a mattress or bed to feed. Pull the bed away from shelving or the wall and coat the legs of the bed with a band of Vaseline or mineral oil with a band about 2 inches wide. Use effective means to prevent or exclude bed bugs from the sleeping area. This could include keeping a zone around the bed "bed bug-free" by careful examination and removal of bed bugs with a stiff brush and vacuum and by caulking cracks and by placing a barrier of chalk or silica aerogel around the bed posts at floor level. Double-sided carpet tape may be effective in trapping bed bugs and excluding them from sleeping areas.  Clear sticky tape is a good way to capture individuals for later identification.

Above: Bed bug expanding in size as it fills up with human blood.

In Massachusetts, Gentrol and Phantom are registered pesticides for bed bug control that can be applied by professional pest control contractors. Gentrol contains the active ingredient (S)-Hydroprene, an insect growth regulator (IGR) that disrupts the normal growth and development of cockroaches and stored product pests, drain flies and fruit flies, as well as bed bugs. Phantom© uses an active ingredient known as chlorfenapyr. It is non-repellent and relatively long-lasting. If residual pesticides are applied, the base of the bed legs is a good place to begin. Mattresses should not be treated with insecticides.

Rather than replacing one mattress with another that is also likely to become infested, consider encasing the mattress with a bed bug tight cover. Bed bugs inside the cover will be unable to feed and will die out.

Since freezing weather will kill bed bugs, you may be able to place suspect furniture outdoors during the winter for a period of time to eliminate an infestation. Do not bring used furniture into the home unless it can be visually inspected in side and out as bed bug free. It is important not to abandon infested furniture and mattresses without first marking them as infested with bed bugs.

6. Frequently asked questions

Question: Can I bring bed bugs home on my shoes?

Answer: Unlikely, bed bugs are active at night, during the day they are hiding in cracks and crevices. Bed bugs are more likely to be spread via pillows, mattresses, bed linen and bedroom furniture.

Question: Can cold kill bed bugs?

Answer: Yes, although the temperature must drop fast, stay below freezing for several days and the bed bugs must not be too deep inside insulated objects.

Question: How can I determine if my bites are caused by bed bugs?

Answer: Itchy bites can be caused by mites, mosquitoes, fleas and lice. To be absolutely sure, you need to collect a bed bug specimen and have it identified by an expert.

Question: How do you kill bed bug eggs?  Do all these spray on products work?

Answer: Most insect eggs are safe inside a shell or chorion which protects them from pesticides.  Bed bug eggs hatch in about one to three weeks depending upon the temperature.  This would mean a follow up inspection after three weeks would be a good idea.  Most residual pesticides last for one month; so theoretically, there should be pesticide still active to kill bed bug nymphs as soon as they hatch from eggs.

You can search the Internet for additional information under the bed bug's scientific name, Cimex lectularius. Please also refer to the Harvard School of Public Health for more information on bed bugs (http://www.hsph.harvard.edu/bedbugs/).

Above: This is a first instar bed bug nymph highly magnified.  This nymph just emerged from the egg and has not yet fed on human blood.  Because this tiny nymph is clear in color and is only 1mm long (1/24th of an inch), it can barely be seen with the naked eye.  The light yellow is the color of the sticky trap showing through the clear body of the bed bug nymph.

Developed by Gary D. Alpert, Environmental Health & Safety, Harvard University