Controlling musk thistle with an introduced weevil

"The musk thistle, Cardus thoermeri* Weinmann, is a species native to Europe. Accidentally introduced to the United States in the late 1800s, the musk thistle has multiplied rapidly throughout the north central region, including the Plains states. The first report of an infestation in Missouri came from Palmyra (Marion County) in 1941. Musk thistle was not recognized as a serious weed problem until about 1960 when it became abundant in pastures, primarily in the northwest and south central part of the state. Its proliferation then, and now (Figure 1), is the result of airborne seed dissemination and by the movement of hay contaminated with thistle seeds to uninfested areas."--First page.Mitchell Roof (Department of Entomology), Benjamin Puttler (USDA Biological Control of Insects Research Laboratory), Laurel Anderson (Department of Agronomy, College of Agriculture)New 4/82/8