The city of Chicago has lost a loathsome crown. It now rests, uncomfortably, on Baltimore’s head. The source of the accolade is pest-control company Orkin.

Moving up nine spots from last year, the biggest city in Maryland has made it to the top of Orkin’s Top 50 Bed Bug Cities list. Chicago had held that top spot for four years running.

The list is based on where Orkin carried out the most treatments — at both residences and businesses — between Dec. 1, 2016, and Nov. 30, 2017. So it necessarily does not capture the entire universe of client calls for bedbug eradication.

“ ‘Bedbugs are the great hitchhiker of the bug world.’ ” — Ron Harrison, Orkin

Making up spots two to five on the Orkin list were Washington, D.C.; Chicago; Los Angeles, which moved up two spots; and Columbus, Ohio. And while New York often gets the worst press about bedbugs — a Victoria’s Secret store was famously de-infested back in 2010 — the Big Apple came in at No. 9 on the list. Sitting at the bottom of the top-50 list are Myrtle Beach–Florence, S.C., and Honolulu.

“Bedbugs are the great hitchhiker of the bug world, and they are very difficult to control without professional help,” said Ron Harrison, an entomologist and Orkin technical-services director, of the survey that came out Jan. 3. “They don’t just hide in beds — they can be found in furniture, bed posts, rugs and even electrical outlets.”

Orkin, a unit of Rollins Inc. ROL, -2.23% , pointed out that it has treated properties for bedbugs in all 50 U.S. states, offering the reminder that the pests are not a sign of poor housekeeping habits. Luxury homes, hotels, movie theaters, schools and public transit have all fallen prey.

Orkin provided a list of tips for keeping bedbugs at bay:

• Inspect regularly — including bed sheets, mattress seams, picture frames, outlets.

• Decrease clutter to make bedbugs easier to spot.

• Quarantine and inspect secondhand furniture before bringing it home.

• Dry infected linens, curtains, etc., on the highest-available dryer temperature to kill the bugs.

And if you’re traveling, abide by Orkin’s rules of “SLEEP” — survey for signs of infestation such as red or brown spots on sheets; lift and look in typical bedbug hiding spots; elevate luggage off floor; examine luggage upon returning home; and place everything in a hot dryer when you get home.

Read:10 best gifts for the traveler in your life

What not to do? Douse infested areas with flammable liquids and risk burning your house down, as one Ohio woman ended up doing. Cincinnati came in at No. 8 on the list of cities with the most bedbug infestations, and an outbreak in the city last month triggered other such incidents and advice from the fire department urging those affected to seek professional help rather than take matters into their own hands.

From the archives:Worried about bedbugs? These pests are a lot more common

Plus:Check for bedbugs, and make sure you don’t bring them home