UPDATE: The Shenandoah National Park has postponed the spraying project due to the weather on Tuesday.

LURAY, Va. (CBS19 NEWS) -- Visitors in the Shenandoah National Park could notice some helicopters Monday afternoon.

According to an alert, the park says the helicopters are staging ahead of work to spray for the invasive species spongy moth caterpillars.

Weather permitting, the spraying will take place Tuesday along Skyline Drive, between mile markers 39 and 51, and in the Skyland and Big Meadows areas.

The spongy moth caterpillar, also known as the gypsy moth caterpillar, is an invasive species that was first reported in the United States in the 1860s. It has slowly been spreading since. 

It has been identified across most of Virginia, causing severe defoliation and crown dieback for trees.

Trees will eventually die if they experience repeated bouts of severe defoliation of more than 75 percent of their leaves.