Ecological Protection Lab FAQs
Hemlock Woolly Adelgids
HWA is parthenogenetic, it reproduces asexually and basically clones itself, and goes through two developmental stages every year. The progredien, or the first generation, develops from February to May in Georgia. During this cycle over-wintering adults lay eggs, which develop into two forms - sexual winged forms and asexual wingless forms. The winged forms require spruce trees to complete their life-cycle which fortunately we lack an adequate spruce in eastern United States. The winged forms die due to lack of suitable hosts. The wingless forms continue feeding and developing on hemlocks. The spring generation reaches maturity by mid-May in GA, when they are ready to lay eggs. The sisten, second generation, "crawlers" that hatch from these eggs in early June, find new needles to settle on and become dormant until October. They feed and continue to develop during the winter and by February of the next year are ready to lay eggs again.
- Predator Beetles are being mass reared by multiple universities and government organizations. The Georgia forests are being supplied by UNG, UGA, Young Harris, and Clemson
- Chemical Controls are widely used throughout the eastern U.S.
- Genetic Engineering is being researched to try and create a HWA resistant strain of Eastern and Carolina Hemlocks.
- Seed Banks and Nurseries have been established. The nurseries are in central U.S., South America, and Australia.
- A strain of Fungus is being researched to control HWA.
Treatment: Biological Controls
- Sasajiscymnus tsugae(St): Imported from Japan it belongs to the Coccinellid family and is a small black beetle about 2mm long. It feeds primarily on adelgids and both larvae and adults feed on all stages of HWA. St is active during the summer and hibernates in the winter. They have two generations a year, just like HWA, and can produce up to 500 eggs in their lifetime. This type of beetle has been released since 1995.
- Scymnus sp: Imported from China it belongs to the Coccinellid family and is a small black beetle, with coppery colored elytra (hard wings). Some species have two black dots on their elytra as well. They prefer to feed on adelgids, but will feeds on aphids to a certain degree. Scymnus adults feed on all life stages of the adelgid, but the larvae need HWA eggs. They are active during the summer and hibernate in the winter. Scymnus produce one generation a year and can lay up to 200 eggs.
- Laricobius nigrinus: A Derodontidae beetle from British Columbia, Oregon, and Washington, who voraciously feeds on HWA on western hemlocks. Laricobius need HWA to develop into adults and will feed on all life stage, though larvae feed exclusively on HWA eggs. These beetles have one generation a year, however, just like HWA they are active during the winter months and aestivate in the summer.
- Merit: (Active Ingredient: Imidicloprid) Can be used by anyone, with caution, and is best applied through soil injections.This product takes longer to kill HWA but typically stays in the tree longer
- Safari: (Active ingredient: Dinotefuran) Can be used by anyone, with caution. This product quickly kills HWA, but will need retreating more often.
“Trees with the healthiest, most foliated canopy improved the least following the reduction in adelgid populations. Trees with little new growth but no dieback recovered the quickest and most densely. Trees in the poorest condition at the onset recovered impressively but more slowly. Trees left untreated remained sparsely foliated, with dieback”.
The state and federal governments are not only doing their best to control the spread of HWA and save the hemlocks, but are also working with multiple universities and organizations on research, beetle releases, and chemical treatments.
- National Forests: USDA Forest Service
- HWA Management Plan
- State Properties: GA Forestry Commission
- State Campgrounds: GA DNR
- Private Property: Home Owner
There are multiple options for the public in order to help save hemlocks on public lands:
- Visit the Parks. Park fees are used to maintain the parks including treating hemlock trees.
- Georgia Department of Natural Resources has played a huge role in treating hemlock trees and spreading information.
- Become a Friends of GA's State Parks and Historic Sites
- Donations to the Ecological Protection Lab
- UNG and Young Harris
- Attend Hemlockfest where all proceeds go towards saving the hemlock trees.
- Contact other organizations such as Lumpkin Coalition, Trout Unlimited, Sierra Club, Georgia Forest Watch, etc. and see what their efforts are in saving the hemlocks.
- Feel free to contact me and I will provide any info I can
- Lumpkin Coalition: PLATT
- Save Georgia Hemlocks:
- Purchase Beetles:
- Jayme Lynne Longo
Owner and Environmental Scientist
Forever Green Environmental Services
P.O. BOX 270
Scranton, PA 18504
“Results have been encouraging when HWA densities on hemlock trees in release areas were compared with those in similar control areas (beetles absent in the area)at least half a mile away. In 1996, adelgid densities on monitored branches in release areas were reduced by 47%-87% in just five months by a starting population of only 2,400 to 3,600 adult beetles, indicating a remarkable shortterm impact of P. tsugae on HWA”
“Other field studies have shown that S. tsugae can reproduce after release, disperse locally, survive heat waves, overwinter, and establish in a variety of different hemlock habitats in Connecticut and other states (Cheah and McClure 2000).”
“Biff Thompson, a forest health inspector from the Maryland Department of Agriculture (MDA) and Brad Onken, a forest entomologist from the U.S. Department of Agriculture (USDA) Forest Service recovered first generation adults of two species of tiny “lady bug” beetles. These insects, about the size of a poppy seed, were released in an effort to control the Adelges tsugae or hemlock woolly adelgid (HWA), a serious pest of hemlock trees. MDA has released three different species of insect predators against the HWA since 1999 and recovered two of them on Oct. 18, 2005. Recovery of the other species, Laricobius nigrinus, was even more encouraging. In May of this year, MDA entomologists, Onken, and Dave Mausel, a graduate student at Virginia Tech, recovered several larvae of this species following a release of approximately 1,200 of the beetles at Rocky Gap last fall.”