Bad year to be a tree 2 - Operophtera brumata

If you had a lateral view,

you would see a half-sized pair of prolegs on A5 in addition to the pair on A6 for Alsophila. The images in Wagner for Alsophila also don't show the broken dark dorsal line we see on your image and on his images for Operophtera.

… john and jane balaban, 7 May, 2010 - 4:29pm

Lateral

I added some lateral views of other caterpillars.

I see proleg on A6, none on A5 (if I count correctly and A1 is the first segment after the hind true legs).

… John F. Carr, 7 May, 2010 - 4:46pm

Moved

Moved from Geometrid Moths.

… John F. Carr, 6 May, 2010 - 9:06pm

With 10,000 + species of moths in North America

or more, we are just too much of amateurs to say for certain. Maybe someone else can be more certain. We would have called all of these images O. brumata, but not with the certainty you may be looking for :(

… john and jane balaban, 6 May, 2010 - 9:04pm

Moved

Moved from Moths. I'm confident in family, at least.

Is there anything else these could be besides Operophtera?

… John F. Carr, 6 May, 2010 - 8:28pm

Wagner talks about brumata being an introduced pest

in Massachusetts. "During outbreaks they enshroud entire trees in silk". "Under outbreak conditions, ground color may be gray-green, smoky, brown, or black."

… john and jane balaban, 6 May, 2010 - 8:11pm

Plant host...

...is Sugar Maple (Acer saccharum).

… John Pearson, 5 May, 2010 - 10:47pm

Wonder if these all might be Bruce Spanworm

Operophtera bruceata, Wagner pg 210??

… john and jane balaban, 5 May, 2010 - 9:18pm

Cankerworm?

How are spanworm caterpillars distinguished from cankerworm (Alsophila pometaria)?

… John F. Carr, 7 May, 2010 - 6:30am

Maybe

I wondered that too. A newspaper story reported concern that this could be a bad year. Do they change color from black to green? I don't have Wagner, and I don't understand what differences are important for ID.

It's almost all O. brumata here, near the coast. Apparently they are indistinguishable from photos.

… John F. Carr, 5 May, 2010 - 9:26pm