[mrs fish]

Looking in my book pic 2 looks like a Yellow Tail or Gold Tail moth larva, it says they like Hawthorn and Sallow but does feed on various trees.

I have seen nests like that before not sure which caterpillar it was but they can devour bushes and trees in no time especially hawthorn, the hairs can also irritate and cause rashes, they blow about in the wind.

The Northern United States are having a outbreak of a moth caterpillar at the moment the "Eastern Tent" moth caterpillar.
These outbreaks happen every few years.