LAST YEAR, THREE of my balsam fir trees looked awful—brown needles, tunnels in the bark, piles of sawdust near the roots. A local arborist identified a sawyer longhorn beetle infestation. Unless we cut down the trees—which were dead—the beetles could kill neighbouring ones too.
We’d seen these creepy insects before—many, but not all, longhorn beetles are native to Canada. Only some longhorns—including some native species—damage trees, and usually only
