Bloodsucking Bed Bugs Creep Back In Stores are now rid of the pests, but experts warn of a bedbug comeback.

July 25, 2010 -- Bedbug infestations are the stuff of urban lore among New York City apartment dwellers. The tiny pests appear to have become the bane of city shopkeepers, too.

In recent days, the bugs forced the temporary closures of a Victoria's Secret and Abercrombie and Fitch. The shops say they've rid their stores of the bugs, but experts say the infestations are just the latest indication of the bedbug's strong comeback.

After mostly being eradicated form the US a half century ago, infestations are so common that New York City formed a Bed Bug Advisory Board in 2009 to focus on preventing infestations.

According to New York City's Housing Preservation and Development department, bedbug complaints in the city have skyrocketed over the past five years, from just over 500 in 2004 to over 10,000 in 2009. In June, the New York state legislature passed a law requiring landlords to give potential renters a "bedbug history" of their property.

And the United States is not the only country seeing an upsurge in bedbugs, which feed on blood, over the past five to seven years. Michael Potter, an entomology professor at the University of Kentucky, says this is a worldwide phenomenon.

"We just finished a global survey of about a thousand pest control companies in 43 different countries," Potter says. "They see the same thing that we have here."

Bedbugs were a rare sight in the United States of the 1950s. A combination of strong pesticides and robust public education kept them at bay, making sightings relatively rare. However, some of the strong pesticides -- such as DDT -- that work best against bedbugs have since been banned.

What's more, the few bedbugs that survived in that time developed some resistance against the most effective family of anti-bedbug pesticides, called pyrethroids.

As a result, bedbugs are much more difficult to get rid of today. Steam-cleaning of clothes and vacuuming are powerful tools against bedbug infestations, but pesticides "are still the meat and potatoes of [bedbug] elimination," says Potter, "and we just don't have pesticides that are as residually potent anymore, which is to say that you have to hit the bug directly now to kill it. Once the deposits dry, there's no lasting protection."

Besides issues with pesticides, there may be other reasons behind bedbugs' resurgence. Potter says no one is quite sure how they made such a dramatic reappearance, but one popular theory among experts is that the exponential expansion of international travel since the 1950s has made the spread of pests much easier. More people have also just become less vigilant about checking for the critters, but more paranoid once they are discovered.

"Back then, if you saw a bedbug, it was just a part of life," Potter says. "Now, you see a bedbug, and you shut down an entire store or a floor of an office building."