Hemlock Woolly Adelgid

lenphillips · 1st January 2008, 04:56 PM

Online Seminars has an article called Hemlock Woolly Adelgid. It will be available for discussion at the website for January and February.
on-line-seminars.com - Hemlock Wooly Adelgid

According to the article, removing heavily infested branches and hitting the tree with blasts of water will make the HVA problem go away. Do you think this will beat a chemical treatment?

mdvaden · 2nd January 2008, 07:27 PM

I'm going to reread the article again prior to taking the test for it, but in the first time through, here's the paragraph that took care of my curiosity about what we experience locally in Oregon with western hemlock...

Quote:

The two Japanese and two western North American hemlock species are much more resistant to HWA than are their eastern North American counterparts. Of these four resistant species, the western hemlock (Tsuga heterophylla) is most similar to eastern hemlock in appearance, growth, form, and utility. Although adelgids do infest these resistant species, they seldom reach densities high enough to cause injury. Therefore, planting resistant Japanese and western hemlocks should reduce the impact of the adelgid in the ornamental landscape. However, the long-term success of these exotic hemlocks in the forests of eastern North America has not been evaluated.

We had 3 western hemlocks ourselves, at our last home in Beaverton, Oregon, and they would get a few hundred or so of the white wooly spots on each tree, but fairly inconspicuous. Over 5 years, it was mild enough to ingore.

I suppose we should be glad that we don't need to arrange a battlefield with these here.

bigshea13 · 3rd January 2008, 12:08 PM

hey. weve got em in ny. they re ruining alota hemis.there are several things you can do to attempt "control" of the little buggers.

dont hang feeders on or near-birds may transmit larvea
water well in time of drought
remove heavily infected branches
remove heavily infected trees {they become resivoirs for adelgids}
DONT fertilize with nitrogen{you could have many times more if you do so}
oils and soaps help but you have to drench entire tree, even the top.
periods of freezing and thawing deplete populations

the wierd thing with them is that they are a sexual. the female lays a couple hundred eggs. the nymph forms transfrom into either winged or wingless adults. the winged ones die after searching for a type of spruce thats not found over here. the wingless ones keep the cycle going.

trees can die in 4 yrs or they can hang on for many. obviously if there are other factors that are working against your tree it makes it harder for your tree to survive

i wonder if there is a way to alter their offspring so that they only hatch winged larvea.

1st January 2008, 04:56 PM	#1 (permalink)
lenphillips Gettin' motoring Join Date: Nov 2007 Location: Massachusetts Posts: 43	Hemlock Woolly Adelgid Online Seminars has an article called Hemlock Woolly Adelgid. It will be available for discussion at the website for January and February. on-line-seminars.com - Hemlock Wooly Adelgid According to the article, removing heavily infested branches and hitting the tree with blasts of water will make the HVA problem go away. Do you think this will beat a chemical treatment? __________________ Len Phillips Administrator Online Seminars for Municipal Arborists

3rd January 2008, 12:08 PM	#3 (permalink)
bigshea13 Afterburner is shakin' Join Date: Nov 2007 Location: hiding Posts: 388	Re: Hemlock Woolly Adelgid hey. weve got em in ny. they re ruining alota hemis.there are several things you can do to attempt "control" of the little buggers. dont hang feeders on or near-birds may transmit larvea water well in time of drought remove heavily infected branches remove heavily infected trees {they become resivoirs for adelgids} DONT fertilize with nitrogen{you could have many times more if you do so} oils and soaps help but you have to drench entire tree, even the top. periods of freezing and thawing deplete populations the wierd thing with them is that they are a sexual. the female lays a couple hundred eggs. the nymph forms transfrom into either winged or wingless adults. the winged ones die after searching for a type of spruce thats not found over here. the wingless ones keep the cycle going. trees can die in 4 yrs or they can hang on for many. obviously if there are other factors that are working against your tree it makes it harder for your tree to survive i wonder if there is a way to alter their offspring so that they only hatch winged larvea.

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