Ecological Protection Lab
Upon importation all beetles were closely studied under quarantine conditions until USDA approval as use as a biological control for the hemlock woolly adelgid.
A small black beetle, about 2mm long, and is compared to a poppy seed. This beetle, which belongs to the family Coccinellidae, has been imported from Japan since the 1990's. It feeds primarily on adelgids and both larvae and adults feed on all stages of the hemlock woolly adelgid.
St is active during the spring and 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.
At optimal conditions the beetles can hatch from an egg in 8 days, and spend around 25 days in the larval stage before it pupates into an adult. The adults are then sexually mature around 3 weeks after pupation.
There are 3 Scymnus species being worked with as control options for the hemlock woolly adelgid. They have been imported from various regions of China since 1996. Like the St beetles they belong to the Coccinellid family and are 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. The Scymnus beetles are more active during the spring and summer and newly matured adults typically overwinter one season before laying eggs. Unlike the St beetles they have one generation a year, and can lay up to 200 eggs.
S. coniferium has a native range that is similar to that of the southern Appalachians.
Both larvae and adults feed on all stages of HWA, however, the 1st instars mortality rate is high if they don't have adelgid eggs or 1st instar crawlers to feed upon.
All three beetles pass quickly through four larval instars and a pupal stage (Lu et al. 2002), with total development time from egg hatch to adult between 25 and 30 days at room temperature, 20°C (68°F) (Wang et al. 2000, Montgomery et al. 2002).
Laricobius nigrinus Fender is a Derodontid beetle that feeds on hemlock woolly adelgid on western hemlocks. This beetle is native to northwestern U.S. and Canada and was collected in 1997 to assess its potential of being a biological control for HWA. Laricobius is active in the winter and its lifecycle syncs up that that of the HWA.
Saving the Hemlocks, one beetle at a time.
The Roots of the Ecological Protection Lab
During a field botany class a few years ago, a seed was planted in Dr. Robert Fuller’s head (professor and Environmental Leadership Center director). The instructor of the class, Mark Warren, owner of the Medicine Bow outdoor school, was expressing the value of hemlock trees to the entire ecosystem and the grave risk they face from the hemlock woolly adelgid (HWA). The seed started germinating as he learned about the efforts to control this noxious pest locally by working with Young Harris College, Clemson University, and the University of Georgia (UGA). These labs have been working with imported beetles that prey on the HWA. Dr. Fuller felt that it was time for the University of North Georga (UNG) to help fight in this battle too. Fortunately, this notion was allowed to sprout. Two people stepped in to help nurture Dr. Fuller's idea. First, Dr. Mike Bodri, Dean of the School of Science and Health Professions, offered his support and bountiful expertise. Secondly, Representative Amos Amerson was able to obtain ample funding to hire a full-time lab coordinator and support the lab in terms of materials and supplies to get the lab up and running. Soon members of the community stepped up and provided their support by volunteering and providing funding and donations. Three local nonprofit organizations, The Lumpkin Coalition, Upper Chattahoochee Riverkeepers, and Georgia Trout Unlimited, bestowed upon us the necessary monetary donations. Local residents even donated refrigerators, 5-gallon buckets, and their time to help support the cause.
The seed that was planted in Dr. Fuller's head was of the tragic decline of the Eastern and Carolina hemlock trees due to the heavy infestation of the HWA. In the early 1920’s HWA was discovered in the western United States, thought to have been brought over in nursery stock. However, the Western and Mountain hemlocks seem to have the same tolerance for these pests as do the native Asian hemlocks where HWA was originally found. Around the mid 1950’s, HWA was discovered in Virginia. It has since posed a threat to the Eastern and Carolina hemlocks which are susceptible to the HWA feeding. The eastern United States lacks native predators to prey upon the HWA along with a natural chemical resistance to the pest. Almost the entire range of the Eastern hemlock and all of the Carolina hemlocks are under attack by this invasive species as it now is found as far north as Maine, as west as eastern Tennessee and northern Alabama, and as south as northern Georgia. HWA can be commonly seen as white fluffs on the underside of the hemlock branches due to the cottony secretions they cover themselves with. This small purplish/brown aphid-like insect feeds on the hemlock trees by piercing the bark and sucking the nutrients out. They can infest and kill an adult hemlock in as little as four years, or less if other environmental stressors, such as drought, are occurring simultaneously with the HWA. Since there are no native predators to the HWA and our native hemlocks play such a key role in our national forests, alternative methods, like the use of biological controls and insecticides, are necessary for HWA population control. Biological controls that have been identified and released throughout the infested areas of the U.S. include small beetles from Asia, Sasajiscymnus tsugae and Scymnus species, and British Columbia, Laricobius nigrinus, which have been found to feed primarily on the HWA. The UNG lab is currently working with three of these predatory beetles, Sasajiscymnus tsugae (a poppy-seed sized black lady beetle that is native to Japan), Scymnus coniferarum (a poppy-seed sized red and black lady beetle native to the Pacific Northwest) and Laricobius nigrinus (a black predatory beetle, roughly the size of a small grain of rice, native to the Pacific Northwest).
The mission of the UNG Ecological Protection Lab is to rear these three beetle species for release in the local forests of northern Georgia. The hemlock woolly adelgid has reached the Dahlonega area within the past decade and has caused devastating results. HWA has two generations, which means that the adults will lay eggs twice in one year. It is during the winter and early summer months that a “crawler” stage emerges and is spread by birds, animals and humans moving through the forest unknowingly picking up these unwanted hitchhikers. Another factor that aids in the HWA's rapid spread is that they are all females and reproduce asexually, requiring no males to produce offspring. This catastrophic explosion of the HWA is why these Ecological Protection Labs are necessary for beetle rearing and releasing into our Hemlock dominating forests. While managed insecticide use can help privately owned trees, it isn’t applicable for forest use and could possibly lead to other vectors moving in. Having a biological control agent that specifically feeds on these adelgids will help control the HWA population. The creation of this lab, the efforts from its workers and volunteers, and the increase of knowledge throughout the community will all aid in this battle against the hemlock woolly adelgid.
Come show your support every first full weekend in November at Hemlock Fest, a festival dedicated to keeping the project alive!