This follows more than a decade of research on the beetles North American cousin. In 1997, Saloms research team imported Laricobius nigrinus, a tiny beetle from British Columbia, to evaluate its effectiveness and safety as a biological control agent. By the end of 2006, scientists at Virginia Tech, Clemson University, and the University of Tennessee at Knoxville had completed more than 22 research-based releases using protocols developed at a Virginia Tech insectory. In all, more than 17,000 British Columbia beetles were released in U.S. forests with encouraging results, in that their research shows that the beetle is establishing at most of the release locations.
Unlike other predators that have been released into the wild, such as the Asian lady beetle, the British Columbian and Japanese beetles only thrive on one food source. If the beetles we introduce cannot feed or reproduce on other hosts, then the natural conclusion is that there is no risk, Salom said.
American scientists first noticed the tiny, aphid-like insect in the West as early as the 1920s, but it was not until the 1950s that they spotted HWA producing its cottony egg masses near Richmond, Va. Unlike hemlock stands in Asia and in the western United States, eastern hemlocks did not co-evolve with an adelgid species and therefore never developed a natural immunity to the insect. Today, HWA infestations span more than half of the geographic range of eastern hemlocks. In Virginia, they have reportedly killed more than 90 percent of hemlocks in the Shenandoah Valley.
|Contact: Michael Sutphin|