The contrast of the smooth, pale gray bark and bright orange leaves of aspen trees in the fall is a sight to behold in Arizona's higher elevations. But this beautiful display is under threat from an ...

What looked like an inanimate object was actually a tiny, sap-sucking insect called oystershell scale. Its diminutive size belies the greater threat it poses to aspens and trees throughout Arizona.

FLAGSTAFF — As flurries started to descend on the forest floor, a team of researchers examined a stand of sickly quaking aspen trees off U.S. Highway 180, just north of Flagstaff. To an untrained eye, ...