Everyone in the Hudson Valley is being asked to go outside and flip over the branches of their trees.

No, this isn't some sort of prank. In fact, it's something that could save the lives of thousands of trees.

The New York State Parks Department is asking anyone who's out in nature this winter to be on the lookout for a pest that is infesting trees throughout the area. The insect is called the Hemlock Wooly Adelgid (or HWA), and it attacks trees by feeding on their sap and literally sucking the life out them.

Alyssa Reid/NYS Parks
Alyssa Reid/NYS Parks

The insect is pretty easy to look for. Just flip over the branches of any Hemlock tree and look for the HWA's fuzzy, whit egg sacks. They're most visible during the winter months, so now is the perfect time to see if trees in your neighborhood have been infected.

If you find them, simply note where the location is and contact the parks department. The NYS Parks Invasive Species Staff can be contacted at 845 256-0579.

You can find out more information about HWA by visiting the NY Parks Nature Times blog.