Laurie Koelling, executive director of the Michigan Christmas Tree Association, and entomologist Robert Haack check Scots pine for pine shoot beetles at a Christmas tree farm near East Lansing.
Ken Hammond
<a rel="nofollow" class="external text" href="https://www.ars.usda.gov/is/graphics/photos/dec95/k7005-9.jpg">United States Department of Agriculture: Agricultural Research Service</a>