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Severe sudden leaf disease in my flowering Hawthorne, The Dalles, OR #753785

Asked June 03, 2021, 2:40 PM EDT

After reading the article in the following link, I am concerned that this is an intractable plant disease and that I should have the plant destroyed. https://www.itv.com/news/channel/2015-06-02/disease-threat-for-blossoming-hawthorn-treesarea But when I look at the picures of Fire Blight, it looks different to what is happening with my tree. I have a quince next to it that are being affected; crab-apple across the street is unaffected. The architecture of the leaf is preserved and the areas between the veins becomes translucent. There are not raised elements. The leaves curl and then fall off-ghost leaves on the ground. Poor thing has not been fertilized in over 13 years. I'll work on getting some pictures.

Wasco County Oregon

Expert Response

Sounds like it could be a skeletonizing insect. You get images to upload and I will refer to your local agent.
Jay W. Pscheidt, PhD, Professor Replied June 08, 2021, 4:12 PM EDT
Thank you.  I found no insects or insect material.  
On Tue, Jun 8, 2021 at 1:12 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied June 09, 2021, 7:27 PM EDT

This does look like a skeletonizing insect is causing damage. Several insects could be causing this damage. My guess, without looking for the insects, is that you have a pear slug problem. Pear slug is somewhat common in the Mid-Columbia region. Here is a good article about it https://pnwhandbooks.org/insect/hort/landscape/hosts-pests-landscape-plants/hawthorn-crataegus-pear-sawfly-pear-slug. I suggest looking for insects that are feeding on the leaves. If you do see something, please take a photo for me. 

An Ask Extension Expert Replied June 09, 2021, 8:44 PM EDT
I just found your response and wrote the above before reading...I wish I would have found the slugs or could say that I saw alot of flies :-(  I am sick thinking that I should cut it down and burn it.


On Thu, Jun 10, 2021 at 2:02 PM Georgia Opheim <<personal data hidden>> wrote:
The Hawthorne is fairly old.  I think it was foundational planting in 1950's.Several years ago, it looked like something splashed on it-the leaves over the sidewalk looked scalded and shriveled.   It lost most of its berries last year.  I was very pleased to see such a healthy bloom this year.  Within one week it is like it burnt up.  No insects seen or snsect webbing or excrement seen.  No unusual bugs.  It is located next to a big quince and much of the spring a large flock played in the quince most spring.  I sprayed it with Neem oil and had an arborist come.  He thought for sure it was an insect.  But after his exam, he was not sure.  I gave him a summary of a bacterial illness that causes fire blight.  There is one branch that has died back.  No obvious weeping bark sore, but there is a blackness to some areas of the bark.   The quince is showing some signs of damage, but healthy branches have grown out.  
 

On Wed, Jun 9, 2021 at 4:25 PM Georgia Opheim <<personal data hidden>> wrote:
Thank you.  I found no insects or insect material.  

On Tue, Jun 8, 2021 at 1:12 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied June 10, 2021, 5:07 PM EDT
The Hawthorne is fairly old.  I think it was foundational planting in 1950's.Several years ago, it looked like something splashed on it-the leaves over the sidewalk looked scalded and shriveled.   It lost most of its berries last year.  I was very pleased to see such a healthy bloom this year.  Within one week it is like it burnt up.  No insects seen or snsect webbing or excrement seen.  No unusual bugs.  It is located next to a big quince and much of the spring a large flock played in the quince most spring.  I sprayed it with Neem oil and had an arborist come.  He thought for sure it was an insect.  But after his exam, he was not sure.  I gave him a summary of a bacterial illness that causes fire blight.  There is one branch that has died back.  No obvious weeping bark sore, but there is a blackness to some areas of the bark.   The quince is showing some signs of damage, but healthy branches have grown out.  
 

On Wed, Jun 9, 2021 at 4:25 PM Georgia Opheim <<personal data hidden>> wrote:
Thank you.  I found no insects or insect material.  

On Tue, Jun 8, 2021 at 1:12 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied June 10, 2021, 5:07 PM EDT

The symptoms on the hawthorn leaves are inconsistent with fire blight symptoms (1), but do display the hallmarks of insect damage, holes between leaf veins (2). Wasco County Master Gardeners will begin accepting samples in July. I suggest bringing samples to the Master Gardener plant clinic when it reopens. 

(1) https://pnwhandbooks.org/plantdisease/host-disease/hawthorn-crataegus-spp-fire-blight

(2) https://pnwhandbooks.org/insect/hort/landscape/hosts-pests-landscape-plants/hawthorn-crataegus-pear-sawfly-pear-slug

An Ask Extension Expert Replied June 11, 2021, 6:39 PM EDT

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