Bedbugs (Cimex lectularius) have posed a problem in the United States since Colonial times. Colonists brought these pests with them on sailing ships.

Once here, these biting insects flourished until DDT became ubiquitous as a pesticide. Families would often put DDT around a bed to keep the bugs at bay. This insecticide nearly wiped out the infestations. Eventually, though, the creatures developed resistance to many insecticides.

There has been a resurgence of bedbugs in apartments, homes and hotels. People often worry that their space has been invaded. That’s why many people have become interested in detecting bedbugs.

Some years ago, we wrote about a simple homemade bedbug detection system.

It utilizes an upside-down dog food dish wrapped in black surgical tape and coated with nonstick spray. In the center is a gallon jug with water, sugar and yeast to produce the alluring (to bedbugs) scent of carbon dioxide.

This do-it-yourself project was described in the Journal of Economic Entomology (August 2013).

We heard from an entomologist regarding this project. He discouraged the use of nonstick spray and suggested an alternative:

“Do not buy any fluon; it’s expensive and completely unnecessary! I would suggest a killing fluid in the bottom of the trough like soapy water or a little vegetable oil. Most people already have this on hand — and dead bugs don’t climb out of traps! Surgical tape is not required, just a surface that is rough so the insects can climb up the walls of the trap.”

An alternate method for detecting bedbugs is to call in specially trained dogs, usually beagles.

This may be a bit pricey but can provide useful information.

Our entomologist commenter warns: “One thing to remember about using canine scent detection is that it only gives you a snapshot of bedbug activity at that particular time. So if a dog gives the ‘all-clear’ on Tuesday and then bugs get brought in on Thursday, you’ve just wasted a couple hundred dollars. Dogs are great for inspecting an entire apartment complex in one day but for the average house or an apartment I would recommend a cheap trap like the homemade one.

“Generally, everyone in a place with bedbugs gets bitten, but not everyone reacts. I personally do not react to bedbug bites, not even a red bump the next day. Spiders are rarely the cause of mysterious welts, as most species will only bite as a last resort. But they are regularly blamed as the cause for bites!

“The most important thing to do when dealing with bedbugs is to figure out how they are getting introduced (where do you go, what do you do, who comes over) and to take proper precautions to avoid the source when possible. If you do find bedbugs, I highly recommend calling a professional.”

Many people try to eradicate bedbugs with insecticides.

That rarely works and could expose people to toxic chemicals. Professionals can use whole room or whole house heat (135-145 degrees F). This usually kills the bugs without leaving a chemical residue behind.

Once a treatment has been completed, bring back the dogs or set up your homemade trap to make sure you have succeeded in eliminating the bugs once and for all.

In their column, Joe and Teresa Graedon answer letters from readers. Write to them in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email them via their website: www.PeoplesPharmacy.com.