I spotted an egg case on the “Tina’ crabapple about a month ago and meant to check with someone to see if I should leave it — if some beneficial insect would emerge — or whether I should remove it — if a destructive little varmint lives inside. But I forgot.
And then today, in my RSS feed, Mary Holland’s wonderful Naturally Curious blog popped up with a photo of my egg case! She identifies it as the egg case of the Rusty Tussock Moth (Orgyia antiqua), and says that it contains lots of little larvae who are just waiting for the right moment to defoliate my little crabapple.
So, as the hosting crabapple is young and needs all its leaves for another few seasons, it was with a slightly heavy heart that I removed the case this morning. The photo below shows it on the windowsill, and you can see that the case looks just like the one in Mary’s photo, if a poorer quality image.
I love being able to identify something, so easily!
But I don’t like killing potential moths. I don’t see how to affix it to another host, though. We have lots of mature apple trees and birches that could take some nibbling.
More on the Rusty Tussock — with photos of several stages — at Wikipedia.