BEDFORD, N.H. – The tree-munching woolly adelgid, like thousands of others in this fast-growing town, may have decided this is a good place to settle down. State officials, however, want it evicted.

Scientists think the aphidlike bug arrived in Virginia from Asia in the 1950s. It’s been spreading outward about ten miles per year ever since, devouring hemlock trees along the way.

It has yet to become well established in New Hampshire, however, and foresters have been on the lookout. It infested some trees in Portsmouth three years ago, but an aggressive campaign there seems to have contained it.

Now scientists are a bit baffled about why the bug has apparently settled in Bedford. Resident Joseph Wudkya spotted the bugs on two trees in his yard recently.

Foresters think the trees have been infested for as many as five years. But they can’t find any signs that the bugs have spread through the surrounding forest.

“I’m thinking that maybe it has reached the limit of its range and it’s adjusting and we’re catching it just as it’s starting to adapt itself,” said Jennifer Bofinger, forest health program coordinator for the state Division of Forest and Lands.

Bofinger said she was puzzled and intrigued that no additional signs of adelgid infestation were found.

The adelgid kills hemlocks by sucking sap from its flat needles, which turn grayish-green and fall. Infested trees have a cotton swablike fuzz on branches.