(Undated) -- Over the Memorial Day weekend, many Illinoisans enjoyed time outdoors and perhaps around a campfire. And state leaders are asking them to do their part to stop the spread of the Emerald Ash Borer. It’s the prime time of year for movement of the bug that has invaded millions of ash trees in the Midwest. Scott Schirmer with the Illinois Department of Agriculture says more than 40 counties are under quarantine to prevent the bug spreading as people move firewood they don't realize is infested. The Emerald Ash Borer is a small, metallic-green beetle native to Asia that was first discovered in Illinois in 2006. Schirmer says since then, it has infested more than 20 million ash trees in the state, many of which have died.