USDA ARS Photo Unit , USDA Agricultural Research Service, Bugwood.org
USDA ARS , USDA Agricultural Research Service, Bugwood.org
Doug Stone, Mississippi State University, Bugwood.org
Clemson University - USDA Cooperative Extension Slide Series , Bugwood.org
John A. Weidhass, Virginia Polytechnic Institute and State University, Bugwood.org
John A. Weidhass, Virginia Polytechnic Institute and State University, Bugwood.org
Rob Routledge, Sault College, Bugwood.org
