Hairy Harry having another bad hair day?

Possibly not. Hairy Harry is supposed to look like this, we think. But then our regular contributor Crafty Pip sent in the photo of something in his garden in Jimena, with the following message: "I have got another for your Lepidopterology experts....Yvonne found this in our Acer Negundo tree , but we have been unable to identify it." Have we any Lepid... Lepidoptol... Lepidio ... ah, never mind. Can anyone identify this thing? Click on the image for a much closer look. (P.S. Wot's an Acer Negundo tree, anyway?)