holes in poplar butt?

[sloth]

I have been told in the past but since forgotten; I have found bore holes in the butt of a row of poplars, all holes about 10mm, at ground level. Only as deep as the cambium, then going down through the inner bark. There are quite a lot on the trees which are affected. Anyone care to put a name to the critters responsible?

[David Humphries]

The MO sounds about right for Sesia apiformis - The Hornet Clearwing

 

A moth that looks a bit like a Hornet

 

Think they emerge in early summer.

 

.

[janey]

I initially thought that too, but the holes are too large at 1cm.

 

So, dunno

[LincolnSteve]

I agree with Monkey-D, certainly will be S. apiformis. Incredibly common on just about every poplar I have seen in Suffolk. It's mostly found in East Anglia and will often lead to decay in the butt. We lost a pop over a road to this and the scary thing was the top showed no sign of any dieback which you would expect with a stem this decayed. The rot stays low and can be hard to spot, you really need to get down and have a good prod around if you find the holes. Some pics below show what can happen (holes vvisable in 3rd pic)

[sloth]

That'll be the one, felling a row of 50 aspen, about 30-40 feet tall along a road, several gone over in that very fashion already in the last few years. On closer inspection they all have it, and associated rot, with what look old armillaria on a few of the worst. Tricky to spot, right in/below the grass.

Thank you