I can't find any HWA at my timberland

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gnmcmartin
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I can't find any HWA at my timberland

Post by gnmcmartin » Fri Oct 03, 2014 12:11 pm

Folks:

Last fall I reported that I have a HWA infestation at my timberland on the Allegheny Plateau in far Western MD. But now I am wondering if the situation, near-term anyway, has changed. As of now I am unable to find any adelgids, not on my timberland, nor on trees in an area nearby, which had a devastating infestation, with trees near death. Those trees look like they are recovering, but the worst affected, somewhat marginally. I have searched diligently, but have not seen a single adelgid.

So, I have a couple of questions. First, it was an extremely cold winter. We did not have anything near the coldest temps on record, but we had numerous cold spells with the low temps between -15 and -20 for several days on end each time. And, in addition, which I think might be significant, we had an extremely unusual cold spell on or about November 20, and then another in the second week of March. I had never in the 40 years I have had my timberland, seen such cold, both early and late.

So, have virtually all the adelgids succumbed to the cold? If so, how long before they might return?

And next, have the predator beetles that have been released survived, or are they all gone also? If there was a species that fed only on adelgids, I expect they will also be gone, but I understand there was one or more kind of beetle that fed on other prey as well.

So, what can anyone tell me? Do my hemlocks have a reprieve? I have had a couple of contacts at the USDA, and one of those was in Elkins, WV, which was covering areas near my timberland. But in the year since I have had discussions with these people, they have moved, or changed jobs. Strangely, I haven't been able to contact anyone I talked to before. If in the coming days I can find someone familiar with the situation in my area, I will let everyone here know what I find out. but for now, all I have is my own wondering.

--Gaines McMartin

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Will Blozan
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Re: I can't find any HWA at my timberland

Post by Will Blozan » Fri Oct 03, 2014 12:52 pm

Gaines,

You, like us here in the Smokies and much of the eastern hemlock's range, are currently blessed with significant winter kill of HWA. Even here in Asheville, NC where it barely dipped below 0 degrees, most HWA are dead. However, as you can imagine, the weak were wiped out and now the more cold hardy will prevail.

They will be back, and if no super-cold in the coming years the trees will be covered rapidly.

One benefit of the HWA mortality is you can treat trees with the cheapest insecticide option out there (since time is not so crucial to get control). Look for LADA 20L. dosage is less than $.06 down here per diameter inch...

I hope you're well!

Will

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gnmcmartin
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Re: I can't find any HWA at my timberland

Post by gnmcmartin » Fri Oct 03, 2014 6:39 pm

Will:

Have you heard anything about the survival of the predator beetles that have been released? If they suffered as much, or maybe even more than the adelgids themselves, we are not any further ahead with that approach. Thanks for the tip on the insecticide, but so far I have not been able to find any time to try to treat my hemlocks, and I won't have any time until at least next fall, if then. I have been hoping, foolishly, perhaps, that the experiments with predator beetles might begin to show more success than has been shown up to now. I am wondering if that would be my only hope.

But, even before this winter kill of the adelgids, my hemlocks were very minimally affected. I had found the adelgids on only about half my timberland, and few, if any trees were noticeably weakened. But not 4 miles away to the east, the hemlocks have been more or less devastated. But now I can't find any adelgids even there.

So, even without this winter kill of adelgids, I had some time, and now maybe a bit more, but failing some hope for a biological solution, I am pessimistic about the chances of my doing anything for my hemlocks.

If anyone could give me a recommendation about what kind of beetle I should buy and release, I would try that even now, in spite of research results being so uncertain, with the hope that before all my hemlocks were killed, they could begin to have some effect. Of course, right now, with no adelgids visible to me, some kind of beetle that feeds on other prey than just the HWA might be the best choice. But, maybe, by next summer I will see lots of adelgids again.

Yeah, I have always been a dreamer.

My timberland is about as pretty as any I have ever seen, but without the hemlocks, it would descend towards the ordinary.

--Gaines

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Rand
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Re: I can't find any HWA at my timberland

Post by Rand » Sat Oct 04, 2014 8:48 am

Yeah, I have always been a dreamer.
I know what you mean. There are a couple of yard ash trees that died back from the EAB three years ago at the same time a bunch of other ash trees flat out died in my neighborhood. About half their crowns died back, but the trees sent up lots of waterspouts from lower down on the big limbs that have been slowly growing back since then. I tell myself that by some unknown alchemy they might survive long term, but I'm probably dreaming...

In a similar vein, I trimmed the competing vegetation away from some chestnuts sprout in recovering clear cuts. They got 4"-6" dbh before the blight got into them, and it takes ~ 3 years for the blight to overwhelm them. They resprouted, but apparently a cold winter is extremely favorable to the blight, because even though the sprouts looked blight free in the fall, a whole bunch were dead by mid-summer.

One the plus side I did get some nuts last fall and have 13 seedlings to plant..uh... somewhere.

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Will Blozan
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Re: I can't find any HWA at my timberland

Post by Will Blozan » Sun Oct 05, 2014 8:02 am

Gaines,

I think it is certainly possible that a cold snap can eliminate any headway made with biocontrol efforts. Millions and millions spent over decades could be erased in a few hours. I know efforts are being made into predators that are specifically cold hardy. But the main issue is diet. A HWA obligate feeder that can survive temps lower than the HWA is as good as dead. This is likely a problem with the Sasajiscymnus beetle.

Will

wisconsitom
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Re: I can't find any HWA at my timberland

Post by wisconsitom » Fri Feb 19, 2016 12:50 pm

Any news on this, guys? I have read-and my eyes confirm-that NE Wisconsin and adjoining Upper Michigan are collectively the last best place to see eastern hemlocks. So far.....and I use that phrase advisedly, HWA is not present here. It would be heartbreaking to see it jump across Lake Michigan and set up shop here. In the neck of the woods around where my land is located, near the tiny town of Suring, WI, hemlock is the main regenerative species in many woods. It really jumps out at you how much hemlock "wants" to grow here.

Getting back to the predatory beetles, one wonders if a coordinated interstate attack were to be initiated-basically a large-scale release across all known HWA and for that matter, hemlock areas, if the pest might not possibly be stopped, at least for now? No small order I realize, and with politics, especially in places like Wisconsin being what they are today, a highly unlikely thing I do realize. Talk about dreaming! Scot Walker giving two sh*ts about hemlock trees?

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gnmcmartin
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Re: I can't find any HWA at my timberland

Post by gnmcmartin » Fri Feb 19, 2016 2:05 pm

NTS:

Still no sign of any adelgids on my timberland, and the hemlocks that had shown some effect have recovered completely. No so those in the area nearby that was so severely infested. They are growing back some, but many of the limbs are dead.

When the adelgids return, I will "panic" again. There are absolutely glorious hemlocks. They are not by any means record breakers for height or diameter, but a good many are 30" or more, and a hundred feet tall or more. In some areas they make up 60 to 80% of the trees. If they all died, these areas would be so ugly I would avoid going there. There are also red spruce mixed in to some extent, and losing the hemlocks could change the environment those are now thriving in, creating a possible "domino" effect.

About 100 acres or more of my timberland have very significant hemlock populations, so treating them when the adelgids come back could be difficult. I stay in shape, do all kinds of conditioning exercises, but I am 76 now, and the prospect of treating all these acres is daunting.

One question that maybe Will or someone else could answer: I drive from Winchester to my timberland along US route 50. Along the route as it passes through the so-called Potomac Highlands before getting to the massive Allegheny Front, none of the hemlocks seem to be affected by the adelgids. This area is well within the huge area where most of the hemlocks have long been infested and killed. How are these escaping? Are they somehow isolated enough from other infested areas?

it is only soon after I have crested the Allegheny Front, and am driving across the Allegheny Plateau, that I find the severe damage, with the trees now trying to recover after the recent killing cold.

--Gaines

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