A noninvasive beetle caught on film in a Cambridge back yard in 2006. City trees are threatened by the Asian long-horned beetle, city, state and federal officials warn. (Photo: boodoo)

If you’re seeing more big beetles this year, there may — or may not — be cause for alarm.

While the beetle population may be up in general, somewhere out there lurks the Asian long-horned beetle, which can decimate the local tree population, targeting maples, elms and others Cambridge has in large numbers, city Arborist David Lefcourt said Wednesday.

“If you see one, save it,” he said of beetles. If it is identified as an Asian long-horned, “we will notify the federal authorities and bring them in.”

His warning came after the year’s second call about beetles or large bugs seen in the city — all over, although the first call was specific to Inman Square. (That one turned out to be a false positive, meaning not be about an Asian long-horned.) Last year, there were three to five calls total with questions about beetles seen in Cambridge, he said, but it’s reasonable that there may be more this year.

“It depends on the season. Weather will have an impact on how insect development takes place. Different insects have different life cycles,” he said.

After six red maple trees were found infested last week on the grounds of Faulkner Hospital in Jamaica Plain, state and federal officials planned a citywide search for the beetles or other affected trees, The Boston Globe reported. More from the Globe:

The beetles are believed to have come from China. They bore into trees and eventually kill them. They mainly attack hardwood trees, including maples, elms, willows and birches. There are no known predators to stop the spread of the beetles, state officials said … After the beetles were discovered in Worcester in 2008, more than 17,000 infested trees were cut down. Another 10,000 were cut down because of their proximity to the infestation.

“There are other threats that knock at our door, but that’s the only one I know about now,” Lefcourt said of the long-horned beetle. Any sighting of a beetle is worth a call to the arborist’s office, though, if the spotter isn’t sure if it’s a noninvasive breed or the Asian long-horned.

And, he urged again, if you can trap it, all the better.

The arborist’s office is (617) 349-6433. Here’s a link to more, and crucial, information about the Asian long-horned beetle.