Release and Establishment of Two Species of Weevils for Control of Musk Thistlein Tennessee

摘要

Musk thistle, accidently introduced into the U.S. from Europe more than 100 yearsago, became a major pest in middle and eastern Tennessee by the 1960s and 1970s. This noxious weed resulted in an extensive annual expenditure of time, labor, and money with the average cost of chemical control of thistle estimated to be $10-15/acre. The University of Tennessee Agricultural Experiment Station in cooperation with the Tennessee Department of Transportation (TDOT) and Federal Highway Administration initiated research programs in 1989 and 1992 to suppress musk thistle using two plant-feeding insects, Rhinocyllus conicus and Trichosirocalus horridus. The release sites for the weevils were along the state highways and interstate system. From 1989 through 1995, about 70,000 weevils were collected and redistributed into thistle-infested regions in 61 countries within the state. Weevils were recovered from as many as 58 counties where head and rosette weevils had been previously released. By 1995, musk thistle density at the original study sites averaged less than 0.5 plants/sq. m., representing a 94% reduction in musk thistle since 1989.