caterpillars eating my weeping birch leafs HELP!!!!!

[Northernfox]

I was out watering tonight and noticed my weeping birch looked a little sparse.... so I got closer and found a bunch of caterpillars were eating the leafs... they hang upside down and are eating fast.... HELP

[img]https://i1262.photobucket.com/albums/ii603/Northernfox14/09c11bce.jpg[/img]

[bangstrom]

For a quick solution, you could reduce the population with garden hose fitted with a high muzzle velocity Rambo style nozzle and wash them off. If that isn't sufficient, you could spray with Bt (Bacillus thuringensis). Bt is specific for larval forms of moths and butterflies so if those are moth larva Bt should work and it is harmless for other living things.

[Kisal]

I think they are one or more of the several species of birch sawfly larvae, possibly the dusky birch sawfly. Here's a site with good information about them:

https://www.entomology.umn.edu/cues/Web/106DuskyBirchSawfly.pdf