Tiny black bugs that startled Pittsburgh Pirates fans last week at PNC Park might crawl around Western Pennsylvania for a few more weeks before they burrow underground, entomologists say. Deluges of yellow poplar weevils began appearing last month across the region, often alarming people who mistake them for disease-spreading deer ticks. Unlike ticks, the vegetarian weevils don’t bite or infect the human body. Jennie Roth, 31, of Bellevue knew the difference when weevils inundated upper seats at the Pirates’ June 26 and 27 home games against the Atlanta Braves, although other fans tensed up. “The place was swarming with them,â€? Roth said of the six-legged insects that tottered across fans’ yellow T-shirts. Adult deer ticks have eight legs. “I was kind of playing with them. What else are you going to do?â€? Roth said. “You don’t want to kill them all.â€? Ornamental entomologist Greg Hoover said the weevil boom reaching into Ohio, West Virginia and farther south appears to be the first outbreak in the area since 1968. The bugs appear every year in late spring before they hibernate by mid- to late July, but Hoover isn’t sure what’s fueling the population explosion this year. The weevils feed only on certain trees, he noted, including yellow poplars, magnolias and tulip trees. Some of their favorites are clustered around Allegheny Center, a few blocks from PNC Park in the North Side, according to a database at www.mytreekeeper.com. “If it’s windy and those folks are in parking lots downwind of the host trees, they very easily could have (weevils) blown on their shirts and clothes as they proceed into the ballpark,â€? said Hoover, who works for the College of Agricultural Sciences at Penn State University. “These things are not that heavy.â€? At about 3 millimeters long, the weevils can look at first like the deer ticks that are concerning public health agencies statewide. Doctors suspect well more than a third of deer ticks in Allegheny County carry bacteria that can lead to Lyme disease, an inflammatory condition confirmed a record 822 times in the county last year. “It’s definitely the new normal,â€? said Dr. Scott Curry, a UPMC infectious disease specialist who sees one or two Lyme cases a week in the summer. He recommends proactive antibiotic treatments for many local patients with bites from engorged deer ticks. That urgency was not the standard a decade ago, when Lyme disease was so rare in Western Pennsylvania that infections from ticks were unlikely, said Curry, who practices in Oakland. “It’s highly unpleasant to get acute Lyme disease,â€? he said. Symptoms range from a bull’s-eye-type rash to flu-like discomfort, joint pain and neurological problems. Fatalities are rare. At the Allegheny County Health Department, medical entomologist Bill Todaro said the comparatively harmless weevils — and the confusion they bring — are making Western Pennsylvanians more watchful for deer ticks. The department has urged precautionary measures against Lyme disease, including using insect repellent with DEET and checking clothes and skin for ticks. “We couldn’t pay for this kind of promotion,â€? Todaro said. “This beetle has brought it home to people.â€? Weevils are often bigger than deer ticks, which are about the size of a dust speck or a punctuation mark — a period — in the nymph stage, he said. A female adult deer tick can grow to the size of a sesame seed. Another distinction: Weevils have antennae; ticks do not. Weevils don’t even kill the trees they feast on, Hoover noted. The leaves might turn a little brown. “I would not give it, as a plant pest, any economic importance,â€? Hoover said. Adam Smeltz is a staff writer for Trib Total Media. Email Newsletters TribLIVE's Daily and Weekly email newsletters deliver the news you want and information you need, right to your inbox.