Sticky shield

Sticky shield

A panel covered with a sticky layer (much like present day flypaper) used to trap insects. Such shields were sometimes made of canvas in the form of a large open-bottomed-and-ended box that was mounted on wheels and dragged (by horse or mule) over a row of plants. One formulation of the sticky layer was paint made by boiling five pounds of rosin in a half gallon of castor oil. It was then applied hot to the canvas.