Recurring Problem Pears Every Late Summer

This comes on my pears late each summer.

Any idea what this is? Does not seem to have any effect for next year but it can’t be good.


I always assumed it was pear scab. Hits Bosc bad, especially this year. I dropped off a couple of branches with my CE agent a couple days ago just to get something definitive. It can defoliate trees and render them useless if it occurs by mid-summer. I’ll let you know what she says.

BTW, did you get my invite?



…And yes responded by PM


I’m curious to hear what it is. The leaves on my Seckel pear look a lot like that now. I’m glad to hear it won’t affect the tree next year. I just got my tree this year, and I was a little worried I was going to lose it after just getting it.

We get this on some of the kiefers but have not seen any branch die back from it rsther just defoliation.

same here, I’ve had it on my kiefer this summer but not to that extent.

It is on several of my 14 varieties of pears.

After the weekend I will post the affected varieties and more photos if warranted by any changes in the leaves.


It’s fireblight. I noticed the first photo has every leaf on the spur affected. Then a scattering of some of the leaves on that same branch are affected. That’s how my pears generally first start to get fireblight (more scattered like that). Then sometimes it burns up the whole branch.

It’s been a bad year for fireblight here with the cool summer and lots of rain.

I might get some disagreement on the diagnosis, because it is affecting your pears late season, but sometimes that’s when fireblight hits my pears. I lost a scaffold of Harrow Sweet this year to fireblight in late season.

It pretty much wiped out a Bartlett this year. Ginger Gold was the only apple which got hit.

Except I get something similar to the photo where branches defoliate but there is no cambium damage to the wood- even the small wood. Only leaves are affected to the point of often defoliating an entire tree. FB seems to always be an easy diagnosis because entire shoots die over night and the wood they are attached to is also dead. Sudden failure of the vascular system of small wood seems to cause the leaves to die immediately and cankers are apparent with some ooze.

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The leaves do not curl or shrivel and there is no “shepherds hook” anywhere.

It almost looks like the leaf damage caused by Pear Psylla in the photos when you Google “Pear Psylla Leaf Damage”
I tried to copy and paste the link here but it seemed to be too big and did not work here.


Yes, it is often associated it with psyla in my experience, but I wasn’t sure if it was a direct or indirect consequence. Psyla is the Achilles heal for pears. But at sites where we do an organic Surround program I haven’t seen an improvement where total defoliation is a problem with Bosc and Surround is supposed to be great for psyla.

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First: This is the best $3.99 that I have spent. I bought this gizmo that fits on the smartphone camera eye and see the photos I took at 30+ magnification
This was a cheapo. I will definitely be looking for a better one.

Second: these things CANNOT BE SEEN with the naked eye. They are smaller than a grain if sand.


I found them by looking at where the jellowjacks were going. These were mainly at the point where the leaf meets the branch. I pulled back the leaf and there they were. You would not see them with the naked eye in 100 years .

SO now the million dollar question.

WHAT do we do now. My pear trees have no fruit.



Great find I’ve got to get a magnifier like that!

As normal your a wealth of information.

Here is some advise from Penn State on controlling them

Usually by now there’s no point but when you come by I can give you a compound that will do the trick. The pictures make me want to kill them now- even if they are almost done for the year.

If you’d mentioned the yellow jackets I could have assured you psyla was an issue. Psyla doo always brings them because it’s mostly sugar and I’ve never seen YJ come to a pear tree that didn’t have psyla **or ripe pears.

Well I was wrong then. But both psylla and fireblight do look a lot alike

See: Tree Fruit Update: July 14, 2014 - CT Integrated Pest Management Program

I’ve not had to deal with psylla here (probably because of my spray program) so I’m not that familiar with it. Learned something new. Thanks for posting Mike.

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I have got to have one of these camera attachments. Amazon has several zoom options. Just wondering if you have any suggestions for an upgrade. Bill

I wonder if you might be on to something. What if the pest causes injury making the trees get the Fireblight. It would be as dangerous as grafting or pruning in Fireblight season. They are in and of themselves reportedly not dangerous but rather cause secondary fungal infections. What if they also cause secondary bacterial infections? I have always thought insects spread Fireblight if the trees are in bloom or not. If a grasshopper chews on a Fireblight infected pear and jumps to the next and chews on it how would he not spread disease?

Mike, those pics are nothing less than fantastic. Great detective work!

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That’s a good point Clark.

Here are several pics I took of a couple of pear trees which got hit with Fireblight this summer. The first pics are a Bartlett which was pretty much wiped out from FB. The last two pics are from a Harrow Sweet (supposed to be tolerant of FB) which was right next to the Bartlett (which is why I think it got FB). Heavier exposure can overwhelm the natural immunity of the tree. Folks were talking about this recently on a commercial apple forum (Google “quorum principle” for fireblight - very interesting).

Notice all the dead shoots in the background (the photo doesn’t show it but there are all kinds of shepherd crooks in the dead shoots, so I’m certain it’s fireblight. Notice the affected leaves in the foreground are not completely dead but only partially affected. I’ve noticed that’s how it generally starts in my trees. It sort of looks like pear psylla symptoms but I’m doubtful it could be pear psylla because I spray my pears practically every time I spray the peaches, for stinkbug control. The compounds I use for stink bugs are also pretty toxic to psylla, so I would be very surprised if the leaves in the foreground are from psylla. I’ll try to get out there and check with a lens in the next day or two.

Here are some more pics.

These last two pics are Harrow Sweet. I cut one scaffold off this tree from FB (completely dead) but I see I still left one attached shoot which died (last pic)

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Sorry I can’t suggest. I had seen these types of things advertised but didn’t think of getting because I was looking at a handheld 10-20 power.

I just happened to be at a place called OLLIE’S (close-outs) and there it was for $3.99 and I picked it up. It is nice but unwieldly when trying to get a moving target. You have to put it on the subject like a microscope slide under the lens. Try that on a moving tree leaf while holding the phone :sweat:.

I will be looking to see if I can find one of these where the lens is at the end of a flexible tube like the one exterminators use to see inside walls.

If I can figure out a way to stabilize the shaking leaf…

Thanx all for the nice words


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