Tyrone Borough Council convened last evening to conduct general business and to be introduced to a severe problem affecting the hemlock trees located in parts of the watershed property and at Reservoir Park – the “Hemlock Woolly Adelgid,” or HWA.
The hemlock woolly adelgid is a tiny insect first detected in the western United States in 1924. It kills eastern and Carolina hemlocks within a few years of first infesting them. The insect in all of its life-cycle stages (eggs, nymphs, and adults) are near microscopic in size, so it is difficult to spot them. But, the sacs that protect the eggs are woolly and white, making the insect recognizable.
The HWA feeds on the sap at the base of hemlock needles, restricting nutrients to the foliage and causing the needles to change from deep green to a grayish green, and then fall off. Without needles the tree starves to death, usually within three to five years of the initial infestation.
Borough forester Paul Noll found the hemlock woolly adelgid and advised council that something had to be done before the hemlock trees became devastated. He told borough officials at the June 9 council meeting that he would check on pricing for two methods of treating the hemlocks – a trunk injection and/or soil drenching.
Certain areas of the watershed are 70 percent hemlock trees, which consists of three main stands. Reservoir Park also has a large population of hemlocks. The disease created already has impacted parts of both, and can impact water temperature and nitrogen factors in the water.
Last night, borough sewer department employee Jim Detwiler, who is also licensed in the specific pesticide treatment that is needed to fend off the woolly adelgid, said that the best way of treating the infestation is through “systemic treatment.”
Systemic treatment of adelgid-infested hemlocks is accomplished with the chemical imidacloprid. It is applied either to the soil and tree’s root zone by drenching or injection, or to the tree itself through a trunk injection system. The solution should be mixed carefully according to label directions and applied either in the spring or fall when the tree is taking up water and nutrients.
The problem with imidacloprid is the environmental consequences that can kill aquatic species and, potentially, some beneficial insects. The soil drenching or soil injection should never be used near open water or in rocky soils that will drain quickly to open water.
If the trunk injection method is used, it is the method most used on trees near open water because it prevents contact between the water and the chemical. Trunk injection projects the highest cost due to equipment that is required and that a professional arborist must apply it, but it is also most effective with large or multiple trees.
Trunk injection also must be done before mid-afternoon because trees cease uptake then.
Detwiler stated it would cost the borough a little over $11,000 to address the problem. The chemicals would cost an estimated $7,800, not including labor, and the equipment would cost around $3,500. If an outside company would come in and do the work needed, he said that it would cost between $160 to $180 per tree.
“We would have to do 400 trees this year,” added Detwiler.
The areas on the watershed that were found to be infested with the hemlock woolly adelgid are not near the projected site of Gamesa’s proposed wind farm. Reservoir Park could suffer a severe loss of trees and create a dangerous situation from the falling limbs of dead trees if the disease isn’t taken care of.
The chemical treatment to stave off the infestation is 98 to 99 percent effective, and is necessary.
Hemlocks may live up to 800 years or more. Their thick, evergreen foliage helps maintain moisture and moderate temperatures on the forest floor. They help cool mountain streams that are home to trout and other native fish, as well as crawfish, salamanders, and numerous aquatic insects.
In the winter, hemlocks moderate ground-level temperatures and help keep streams ice-free. Many birds find shelter and places to nest, such as the wood thrush and warblers.
Hemlock woolly adelgids are bourne by winds or carried by migratory birds, mammals, and humans. Adelgid populations can increase dramatically, since all of the adelgids are female and they reproduce asexually twice a year. One insect can lay up to 300 eggs yielding up to 90,000 new adelgids in one year.
Due to the extremity of the situation, the borough council decided to move forward with protecting the hemlocks in the infested areas of borough property.
Council members Jennifer Bryan and Mark Kosoglow were absent from the meeting, but the remaining council members voted in favor of addressing the adelgid problem. Councilperson Steve Hanzir voted “no” due to the lack of further discussion on the project.
(Some of the information in this article was taken from www.saveourhemlocks.org.)
Tyrone Borough Council approved the following items on its agenda at the July 14 regular meeting:
• The hiring of Open Door Visions to run the borough’s web site.
• A donation in the amount of $100 and a family pass for the community pool for Tyrone Community Day at DelGrosso’s Amusement Park.
• The waiving of vendor fees for the Joshua House’s HoopsFest 2008.
• Final payment to Ag Air, LLC for the gypsy moth spraying of 3,419 acres at a cost of $122,502.77.
• Borough workers compensation renewal through MRM at a premium of $80,937 with an estimated future dividend of $15,690, creating a total estimated premium of $65,247.
• Ordinance No. 1266, Sewer Use Ordinance and Resolution No. 2008-12, Industrial Pretreatment Enforcement Response.
• Mayor Jim Kilmartin declared a proclamation that August 2 will officially be recognized as Colonel James E. Crowther Day.