ANN ARBOR, Mich. – A Michigan city has a message for its residents: There’s nothing sweet about tapping publicly owned trees for maple sap. As the weather gets warmer, Ann Arbor is warning people not to poke trees in parks or along streets. "When we find this equipment, staff will remove it,” city spokesman Robert Kellar told MLive.com. “Tapping causes damage to these trees, which already face challenges, and leave them susceptible to insects and disease.”It's OK for an Ann Arbor resident to tap a maple on their own property, the city said. Ann Arbor says a 16-inch-diameter sugar maple at a home provides $149 in benefits each year, especially in energy savings.

View of a section of Sleeping Bear Dunes National Lakeshore park and fog-obscured Lake Michigan beyond, Michigan, November 2013. (Photo by Interim Archives/Getty Images)HONOR, Mich. – A small insect that can kill hemlock trees by feeding on their sap has been detected at the Sleeping Bear Dunes National Lakeshore in northwestern Michigan. Michigan has been combating hemlock woolly adelgid since 2006 and has current infestations in Allegan, Ottawa, Muskegon, Oceana and Mason counties. The insect was detected in October in Ludington State Park, about 70 miles (112 kilometers) south of Sleeping Bear Dunes. Cars, boats or recreational vehicles parked beneath infested trees may also be able to transport the insects to new locations.