Silver Birtch/ caterpillars

[Guest]

Hi all, my friend has a silver Birtch in his garden and it's just all of a sudden got hundreds of caterpillars  on it any idea what it can be? 

[daltontrees]

Craesus latitarsus. Look it up.

 

[PC Treescapes]

Silver Birch sawfly, squash them all, they will strip all the leaves if a young tree, in no time at all. Had then in two small standards we planted at home, did so much damage in a few days, now super vigilant each year, had some this year and in 24 hours it went from no visible damage to one limb nearly stripped!

[PC Treescapes]

Assume on a large established tree they are much less of a problem

[Khriss]

Never seen them - and I like Betula's K

[timbernut]

Had them on couple of young hazels a few years ago, they were voracious but the birds did for em I think, quite interesting how they all froze in unison as an a shape when you touched the branch. Can they b a problem?

[timbernut]

Craesus latitarsus. Look it up.
 

Looked em up but shows their distribution as USA?
But Craesus septentrionalis native here? I’m no expert!

[slack ma girdle]

Looked em up but shows their distribution as USA?
But Craesus septentrionalis native here? I’m no expert!

Not listed in Moths of the British Isles

[slack ma girdle]

I am fairly sure that it is a saw fly catapillar

[timbernut]

Wasn’t questioning it being sawfly just what sort as distribution for the former seemed to b north America the latter uk