Hemlock Woolly Adelgid (HWA)
Hemlock Woolly Adelgid (HWA) is an invasive aphid-like insect from Japan first found in West Michigan around 2018. It feeds voraciously on Eastern Hemlock trees, killing them within 4-10 years of initial exposure.
How can you identify HWA?
Unfortunately, HWA has become extremely common in West Michigan, with many hemlocks requiring immediate treatment to survive.
HWA is easily identified by its white, woolly egg sacks on the undersides of hemlock branches.
HWA infested hemlocks also take on a thin, generally unhealthy appearance as the infestation worsens, with branches often dying from the ends moving inward.
Damaged trees also become susceptible to secondary pests and diseases.
Click on the images for more information
Click on the images for more information
What can be done for trees infested with HWA?
Multiple treatment options exist for infested hemlocks, but without treatment hemlocks with HWA are certain to die.
In residential settings, horticultural oils, insecticidal soaps and root-drench insecticides, as well as HWA predator insects are all viable DIY options for property owners. Two commercially available insects are S. tsugae and L. nigrinus, small beetles which specialize on adelgids and can create self-sustaining populations in the environment they're released in. If opting for a professional service, certified pesticide applicators can treat larger numbers of trees at a lower cost, such as trunk injections and basal bark sprays.
In a forest setting, HWA predator insects the most realistic long-term solution, but pesticide applications are cheaper and more reliable in the short term, especially with trees already damaged by HWA.
Oriental Bittersweet
Oriental Bittersweet is an invasive vine introduced to the US from East Asia. This woody vine is extremely aggressive, choking out entire ecosystems, replacing forests, dunes and prairies with a dense blanket of vines.
How can you identify Oriental Bittersweet?
Oriental bittersweet is easily identified by its woody stem which winds in a spiral around trees, fences and light poles.
In the fall, it is clearly indefinable by its red and yellow berries, which are sometimes displayed ornamentally.
Where no trees are present, Oriental Bittersweet grows as a shrub, forming a thick mat of foliage which prevents anything else from growing.
Click on the images for more information
Click on the images for more information
What can be done about Oriental Bittersweet?
Left untreated, Oriental Bittersweet completely dominates the area it's in.
Oriental Bittersweet can be killed mechanically (hands and tools). Small vines can simply be pulled to remove the root system. Large vines (6+ inches in diameter) can be cut and the root system usually does not survive. For smaller vines which cannot be uprooted, the vines can be continuously cut until the root system runs out of energy, or cut-stump treatments can be utilized for greater efficiency and in larger areas.
Herbicidal sprays may be used for matted areas, but caution must be taken not to kill desirable, native plant species which may come in contact with the herbicide, either directly or through the soil. Matted bittersweet can also be mowed, but this must be done consistently
Unfortunately no biological controls are available for Oriental Bittersweet.
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