Sycamore trees all dead

[LarDavid]

Over the last five years all of the massive sycamores on our land and in the adjoining area have all died. We cut one up and found worms on the inside, huge white boring worms. I took pictures they are about2-3 inches long with black head. What is wrong?

 

[buzz sawyer]

Never heard of that with Sycamore. Maybe you can ID the worm here? https://www.google.com/search?q=big...UhhuAKHUxMBVYQ_AUoAXoECA0QAw&biw=1536&bih=719

 

[Woody912]

Over the last five years all of the massive sycamores on our land and in the adjoining area have all died. We cut one up and found worms on the inside, huge white boring worms. I took pictures they are about2-3 inches long with black head. What is wrong?

Someone with more knowledge will jump in shortly but my bet is the worms are postmortem. Sycamores are subject to anthacnose ( I think) particularly during cold wet springs. Looked at a bunch of dead tulip trees last spring with state forester, thought aphids had killed them. His response was that aphids alone did not but south exposure, drought and aphids all combined probably did. Your situation may be similar.

 

[ATH]

I'd agree large worms (likely one of the native long-horn beetles...certainly hopefully not Asian Longhorn beetle...Sycamore is a host).

Anthracnose doesn't kill Sycamore. It can stress them, but isn't a primary COD.

 

[Woody912]

I'd agree large worms (likely one of the native long-horn beetles...certainly hopefully not Asian Longhorn beetle...Sycamore is a host).

Anthracnose doesn't kill Sycamore. It can stress them, but isn't a primary COD.

Found a Penn State list of pathogens of sycamore, neither disease nor insects were shown usual COD of sycamores.

 

[andy]

Maybe “ Southwest “... where are they located and how has winter been ?
Would maybe be strange for mature trees but it happens.
Have you cleared/trimmed around them recently exposing the trunks to winter sun?
Is the bark in south/west sides in good shape or is it bubbled up and loose ?

Might be a long shot but never know.
Since you say they all died a pathogen is usually first in suspect list.
Southwest can make it easier for pathogens to take hold.
I’m seeing some fresh southwest issues on a couple magnolias on a new clients property... so it’s on my mind.