Hemlock Wooly Agelgids - Ask Extension
My Hemlocks are afflicted with this bug. Please give me your best recommendations for treating this bug.
Knowledgebase
Hemlock Wooly Agelgids #874009
Asked June 20, 2024, 9:02 PM EDT
My Hemlocks are afflicted with this bug. Please give me your best recommendations for treating this bug.
Anne Arundel County Maryland
Expert Response
Hemlock Woolly Adelgids are a serious pest that will kill your trees if not remedied.
Here is our page on them and how to get rid of them:
https://extension.umd.edu/resource/hemlock-woolly-adelgid-trees/
If the trees are large and/or you don't want to make repeated, timed sprays of horticultural oil, you could have a Maryland-licensed, certified pesticide applicator treat them for you.
The pesticide used is not allowed to be used by homeowners since it can end up in flowers and hurt pollinators- however, these trees are wind pollinated, so there is not a concern for use in this way.
Christine
Here is our page on them and how to get rid of them:
https://extension.umd.edu/resource/hemlock-woolly-adelgid-trees/
If the trees are large and/or you don't want to make repeated, timed sprays of horticultural oil, you could have a Maryland-licensed, certified pesticide applicator treat them for you.
The pesticide used is not allowed to be used by homeowners since it can end up in flowers and hurt pollinators- however, these trees are wind pollinated, so there is not a concern for use in this way.
Christine
Dear Christine,
My understanding is that I shouldn't try to cure my Wolly Adelgid problem myself, by state law.
In any event, I'm 82. It would be a problem.
Would you please recommend some companies I might consult to solve my problem?
I've had no luck in securing a tree service company to solve the problem.
Dan
Hello Dan,
Use of insecticides belonging to the chemical class called neonicotinoids (or neonics for short) are indeed regulated in Maryland, where only certified pesticide applicators can purchase and apply them outdoors. While Hemlock Woolly Adelgid can be successfully treated using neonics, through a hired applicator, it isn't the only option, though admittedly it's probably the most effective and faster-acting option.
Extension doesn't collect information about what landscaping companies exist and what they offer, nor do we make recommendations for particular businesses, but you might be able to find suggestions via other gardeners, either through online forums or on social media (if you use it). Many certified arborists also hold certification to apply pesticides, and you can search for arborists using tools like the ISA's website (the accrediting organization, via the linked page). Maryland licensed tree experts go through similar training and also probably also hold their applicator's license. The Maryland Department of Agriculture, the agency granting pesticide certifications, has an online lookup tool, but admittedly it's not very easy to use.
Miri
Use of insecticides belonging to the chemical class called neonicotinoids (or neonics for short) are indeed regulated in Maryland, where only certified pesticide applicators can purchase and apply them outdoors. While Hemlock Woolly Adelgid can be successfully treated using neonics, through a hired applicator, it isn't the only option, though admittedly it's probably the most effective and faster-acting option.
Extension doesn't collect information about what landscaping companies exist and what they offer, nor do we make recommendations for particular businesses, but you might be able to find suggestions via other gardeners, either through online forums or on social media (if you use it). Many certified arborists also hold certification to apply pesticides, and you can search for arborists using tools like the ISA's website (the accrediting organization, via the linked page). Maryland licensed tree experts go through similar training and also probably also hold their applicator's license. The Maryland Department of Agriculture, the agency granting pesticide certifications, has an online lookup tool, but admittedly it's not very easy to use.
Miri
