Grazing sheep can be an effective, low-cost tool for controlling
alfalfa weevils, Montana State University research reveals. In a
study on a commercial sheep operation, the researchers found
that grazing reduced alfalfa weevil adult populations by 35-100%
and weevil larvae numbers by 40-70%, depending on sampling date
and study year. They evaluated the use of sheep as an
alternative solution for controlling alfalfa weevils, wheat stem
sawflies and other pests in three studies funded by USDA’s
Sustainable Agriculture Research and Education (SARE) program.
Their findings and recommendations are outlined in a new SARE
fact sheet, Sheep Grazing to Manage Crop Residues, Insects and
Weeds in Northern Plains Grain and Alfalfa Systems. It also
covers key details of animal selection, stocking rates, timing,
economics and other issues. “Arthropod pests alone cause an
estimated $260 million in alfalfa damage each year across the
U.S.,” SARE officials wrote in announcing the fact sheet.
“Traditional control methods come