"The most difficult, challenging pest problem of our generation."

The American way of life is facing a new threat, one as profound as climate change or pandemic flu.

Bedbugs.

OK, that's a bit hysterical. But without DDT and the other now-banned pesticides that kept bedbugs in check for more than 50 years, the United States is as vulnerable as parts of the world where the insects remain a plague.

From New York to Los Angeles, and everywhere in between, these apple-seed-size vampires are spoiling sleep, vacations, and the bottom line of just about every business except pest control. Not just hotels and apartments, but nursing homes, schools, churches, movie theaters, cruise ships, subways, fire stations - in Manhattan, even such tony retailers as Victoria's Secret - have struggled to vanquish the vermin.

"This is the most difficult, challenging pest problem of our generation," University of Kentucky entomologist Mike Potter declared in April at the Environmental Protection Agency's first-ever National Bed Bug Summit.

Getting rid of bedbugs is costly, complex, and arduous. But ignoring them - and their intensely itchy, icky, intimate bites - is about as easy as ignoring the Internal Revenue Service.

Just ask the IRS. To the chagrin of the federal tax-collection agency, its Northeast Philadelphia campus has had to battle the bloodsuckers.

"Upon being made aware of the presence of bedbugs," IRS spokesman Mike Hanson wrote in a terse e-mail, "IRS leadership implemented actions to remove these insects."

Not according to Brian Rudolph, head of the union chapter that represents the 4,000 employees who work at the Roosevelt Boulevard campus. After eight months, he said, the place is still bugged.

Formidable and prolific

How can a creature that doesn't fly, jump, or (thankfully) transmit any known disease be so formidable?

It's simple, said David Manos, assistant housing director at Pennsylvania State University, where he has debugged 22 dorm rooms since the first dumbfounding infestation in 2006: "They're cryptic, prolific, durable, and hitchhikers."

A newly infested mattress may appear pristine, so the lack of telltale signs - molted exoskeletons, fecal stains, burped blood - is no reassurance.

Bedbugs can survive a year without food - namely, human blood - and they will go on the crawl for it if you switch beds.

A single female can lay several hundred eggs during her year of life - the egg sacs are transparent, stick to anything, and are impervious to available pesticides - and each of those offspring can reproduce within a few months.