What is this monster in my lemon tree?!

[scribbledaway]

What is it???  There are dozens of it all over my tree!

http://i192.photobucket.com/albums/z110/scribbledaway/monster3.jpg

http://i192.photobucket.com/albums/z110/scribbledaway/monster2.jpg

http://i192.photobucket.com/albums/z110/scribbledaway/monster.jpg