Infestations of bed bugs are on the increase...

1. How to identify and collect bed bugs

Immature bed bugs are light yellow in color unless they have recently fed on blood and then they are darker in the middle. Adults are reddish brown and they also turn darker after a blood meal. Even though bed bugs are small, about 1/5 th of an inch, they can be readily seen with the naked eye. 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. 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. 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.

Bed bugs should be collected into small leak-proof containers of rubbing alcohol. Bed bug specimens should be sent to a knowledgeable expert for positive identification. Dr. Richard Pollack at the Harvard School of Public Health can identify bed bugs sent in from Harvard University.

2. Bed bug biology and behavior

After feeding, a female bed bug will lay eggs in their daytime refuge of cracks and crevices. 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. 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.

Spiders, mites, ticks, mosquitoes or even lice can also cause itchy bites, and these pests require different control methods.

3. 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.

In Massachusetts, Gentrol and Phantom are registered pesticides for bed bug control and 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.

4. 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.

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/).

Developed by Gary D. Alpert, Environmental Health & Safety, Harvard University (617-495-1983)