It's been more than two months since an emerald ash borer infestation was first discovered in Minnesota, and so far, there has been little physical evidence indicating the beetles have spread.
But experts say it's only a matter of time until the destructive pest moves beyond the St. Paul neighborhood where dozens of infested trees were cut down this spring.
State Ag department entomologist Mark Abrahamson says the bug itself is hard to find, even with 1,800 traps set up around the Twin Cities.
"We have caught two beetles so far, one has been immediately right in that neighborhood, very near where we removed infested trees, and then we caught another beetle just about a half mile east of the neighborhood."
Abrahamson says crews have only checked a fraction of the kite-like traps, so more bugs may show up yet this summer.
The tiny green beetles lay their eggs in the bark of ash trees, and the larvae eat the living tissue under the bark, often killing the tree.