Ah ha! I found it! Thank goodness for our lovely search feature on ATP! I put lime tree into the site wide search box & viola'!
The creatures from mars on your lime tree are Giant Swallowtail Butterfly larvae.
Don't kill them please.
I am a strong believer in the simple fact is that what matters in this life is how we treat others. I think that's what living is all about. Not what I've done in my life but how I've treated others. ~~ Sharon Brown