Golf Course Management magazine is dedicated to advancing the golf course superintendent profession and helping GCSAA members achieve career success.
Issue link: http://gcmdigital.gcsaa.org/i/385759
72 GOLF COURSE MANAGEMENT 10.14 Today L. nigrinus can be found in a 35- mile ring around Grandfather Mountain. Its presence is a primary factor in the health and regrowth of hemlocks in the watershed of three river systems that have their headwaters on the mountain: the New, the Watauga and the Catawba rivers. As for Gerdon and his list of what-ifs, "The answers are all around us," he says with a sweeping gesture encompassing the grounds of Grandfather G&CC. "Wild beetle insecta - ries on this property continue to expand, and we are saving hemlocks." To the skeptics, those for whom only see - ing is believing, Gerdon has these words: "I invite anyone who's interested to come visit us at Grandfather Golf & Country Club. I'll show you what we've done here, and then I'll take you to places where the gray ghosts of hemlocks blight the view, a sad reminder of what might have been. For my part, I've got proof that this program works, and I'm just tickled pink." Smile. Wink. Kate Cahow is a freelance writer and photographer based in Boone, N.C. Her husband, Richard McDonald, Ph.D., is the entomologist working on the hemlock woolly adelgid biological control project at Grandfather Golf & Country Club. A version of this story previously appeared in the Jan.-Feb. 2014 edition of Carolinas Green, the publication of the Carolinas GCSA. Bright green needles on the hemlock in the foreground indicate new growth, a sign of Grandfather G&CC's success in controlling the hemlock woolly adelgid. Chemical and biological control of hemlock woolly adelgid Chemical control, 2003-2007 • Kiortz soil injections were used on large- to medium-sized trees at Grandfather G&CC: applied in two concentric rings around trees at 3-foot and 6- to 8-foot inter- vals from trees. • Mauget injections were used on hemlocks within 100 feet of waterways and injected into 12-15 holes drilled 4 feet up from the ground. • Visibly stressed trees were treated with Stemix, a micronutrient package earmarked for hemlocks; capsules were inserted into existing holes from Mauget injections. Biological control, 2008-present Laricobius nigrinus, the winter predator • Laricobius nigrinus females lay their eggs in adelgid egg sacs during the spring; L. nigrinus larvae hatch and feed on adelgid eggs and crawlers, causing 90 percent or greater mortality of the adelgid. • As of 2014, approximately 14,000 wild-caught L. nigrinus adults have been released at more than 40 sites on Grandfather G&CC grounds. • Within three years, L. nigrinus was established at Grandfather G&CC and contribut- ing signifcantly to the mortality of the adelgid, both on the club property and in the surrounding region. • Today L. nigrinus continues to be recovered throughout the Grandfather G&CC grounds and is spreading rapidly beyond the club's borders. • Grandfather G&CC holds the largest release record of L. nigrinus on the East Coast. Scymnus coniferarum, the summer predator • Scymnus coniferarum is a small black and gold ladybeetle that feeds specifcally on hemlock woolly adelgid. It is the summer equivalent of Laricobius nigrinus. Having multiple predators that feed on successive generations of a pest is called "bracket- ing." Both predators attack all life stages of the adelgid and hold it in balance. • A release of 1,000 S. coniferarum adults was made in spring 2013; subsequent re- coveries were made in April, May and June. Northwest by McDonald and a U.S. Forest Service researcher in 2006. This summer- active beetle is a natural complement to the winter-active L. nigrinus, creating an aggres - sive tag team for attacking the adelgid. Both L. nigrinus and S. coniferarum have been ap - proved for release on the East Coast by the state of North Carolina and the U.S. Depart - ment of Agriculture. A shining future for hemlocks The work done at Grandfather G&CC shows how a biologically based pest manage - ment program for hemlocks is practical and effective for large-scale acreage. McDonald calls the program a "shining success for the High Country." "Because Pete, Norris, club members and their board of directors were willing to take a chance on this until-now-unproven pest management approach, Grandfather Golf & Country Club's 1,100 acres are lush with healthy hemlocks," McDonald says. "And they've saved not only their own hemlocks, they're helping to save and protect the entire region's hemlock ecosystem."