India, Oct. 27 -- Leafy spurge has long posed a stubborn challenge for ranchers and land managers across North America. The Eurasian perennial weed can spread rapidly across rangelands and is difficult to suppress because of its extensive underground root system. Its persistence has prompted researchers to look beyond conventional herbicides and mechanical removal for ways to bring infestations under control.

According to the U.S. Department of Agriculture's Agricultural Research Service, scientists in 1988 released 88 flea beetles near Valley City, North Dakota, as part of an effort to control leafy spurge. At the study site, the agency reported that leafy spurge stem density fell from about 182 stems per square yard to five by 1994. Th...