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Because healthy forest ecosystems are vital to the quality and quantity water resource protection and water supplies, we should aware of these forest threats. Forests cover reduces erosion and sedimentation, generally improves water quality and in many cases, forested lands capture and store water. Forests help to maintain groundwater levels and natural stream flows (volumes) throughout the year, and help to reduce the treatment costs of municipal water supplies.
Thus far only the Hemlock Wooly Adelgid has been observed in New Hampshire but the Asian Longhorned Beetle has established in Massachusetts and the Emerald Ash Borer is established in many Midwest states, New York, Pennsylvania and Quebec.
Asian Longhorned Beetle
Adult Asian longhorned beetles are large (0.75 - 1.50 inches long) with very long black and white banded antennae. The body is glossy black with irregular white spots. Adults can be seen from late spring to fall depending on the climate. Females chew through the bark down to the cambium/phloem interface with the xylem, and then turn around and inject an egg (one egg per oviposition niche or site) into the tree, creating a visible oviposition scar on the surface of the tree. Eggs sites are oval or round wounds in the bark (up to 0.5 inch diameter).
Attacks many tree species. ALB attacks many hardwood trees, such as maple, elm, horsechestnut, ash, birch, poplar, willow and many more. These trees represent many billions of dollars to the U.S. economy by supplying lumber, wood products, maple syrup, and promoting tourism.
•Kills Trees. ALB kills young and mature trees by tunneling within the trunk and branches, disrupting sap flow and weakening the tree.
•Potentially disrupts forest. Because this beetle attacks many different tree species, it could significantly disrupt the forest ecosystem, if it became established over a large area.
•No controls. No chemical or biological control methods are currently known, although the USDA - APHIS is conducting experiments testing the effectiveness of some insecticides.
Emerald Ash Borer
EAB is an invasive wood boring beetle that feeds on the tissues under the bark of ash trees (Fraxinus spp) and kills them. EAB is 100 percent fatal to our native ash trees of any size, any age, healthy or unhealthy. Larvae have developed in trees and branches ranging from 2.5 cm (1 inch) to 140 cm (55 inches) in diameter. Stress likely contributes to the vulnerability and rapid decline of infested ash trees. However, emerald ash borer has killed apparently vigorous trees in woodlots and urban trees under regular irrigation and fertilization regimes. A tree that has been attacked by EAB can die within 2-4 years. It is estimated that more than 50 million ash trees are dead or dying in the Midwest because of this insect.
Hemlock Wooly Adelgid
The Hemlock Woolly Adelgid is a sucking insect that is like an aphid. You can find Hemlock Woolly Adelgid by looking for small cottony masses at the crotch of the needles.
It has no natural enemies and it has spread throughout the eastern United States creating an extreme amount of damage to natural stands of hemlock, specifically eastern hemlock.
Moderate hemlock woolly adelgid populations may cause a reduction in tree health while severe infestations result in premature needle drop, reduced twig growth, dieback, or death of trees.
If you have seen these pests, please report the sighting to one of the agencies below.
Much more information (including many images/photos) is available through internet searches:
New Hampshire Division of Forests and Lands: Forest Health
USDA Forest Service
UNH Cooperative
(try Google Image Search for more photos)
Date published on web site:
11-18-2009
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