Urbana, Ill.

I had been a professor of entomology for 15 years before I saw my first live bedbug. It crawled out of a plastic film canister that had been mailed to me by a distraught student in the Boston area who had no idea what it was. I was so thrilled to see a live bedbug, I showed it off to every graduate student I ran into that day: Cimex lectularius  a small, flat, wingless, brown ectoparasite that hides in cracks and crevices in human dwellings and emerges under cover of darkness to feast on human blood.

That was in 1995, and none of my students had laid eyes on Cimex lectularius either. A century ago, bedbugs were ubiquitous in New York  so much so that their presence in an apartment wasn’t considered sufficient legal cause for withholding rent. Bedbugs, one judge remarked in an early 20th century lawsuit against a landlord, “can be dealt with by the tenant by processes known to all housewives.” But with the midcentury advent of synthetic organic insecticides, these insects all but vanished from urban landscapes (and pretty much every other kind of landscape) in North America.

My Bostonian bug turned out to be one of many on the forefront of an unprecedented resurgence. Global travelers now bring in a steady supply from around the world, inconspicuously undeclared in checked bags and carry-on luggage. Today, bedbugs have been found in all 50 states, as well as Guam, Puerto Rico and American Samoa, and bedbug-related calls to pest control operators are escalating at a fantastic rate. From June 2009 to June 2010, there were more than 31,000 calls in New York City alone.

Now, bedbug-related lawsuits can lead to thousands of dollars in punitive damages for mental anguish, embarrassment or humiliation.