About a week ago, around 9 am (may be important?), I found 15 to 20 bright yellow caterpillars apparently coming out of the ground, spread out about 24 inches, and starting to climb the tree.

I saw no evidence of holes in the ground; have been doing stuff around the tree almost every day and have never seen anything out of the ordinary, so not sure exactly from whence they came. Have never seen this specific type before; neither has my wife.

I tried an internet search to no avail. Can anyone identify them?

re ... About a week ago, around 9 am (may be important?), I found 15 to 20 bright yellow caterpillars apparently coming out of the ground, spread out about 24 inches, and starting to climb the tree.

sorry i cant answer your question ..

i found them on a tree on the west side of the moat in march

but like yours i couldnt see any holes in the ground and they kept appearing and climbing the tree

for about three days but ive never seen any more since

dave2

pc .... good pic : )