A Droll Bug Indeed

Meet Diapheromera femorata one of the coolest insects around these parts.  This is a bug that literally looks like a twig or a stick that can walk.   Consequently, it is commonly referred-to as a walking stick bug.  This insect is equipped with possibly the most efficient of natural camouflages on earth.   It and the - equally inconspicuous - leaf insect comprise the Phasmatodea order; of which there are approximately 3,000 species worldwide.   

The name Phasmatodea comes from the Greek term phasma, which means phantom or ghost – a direct reference to this camouflage.   A nocturnal feeder this camouflage keeps the walking stick hidden from predators during daylight hours.  Yet it isn’t their only line of defense. Different species also have thorny spines, or they’ll shed and sacrifice a leg if grabbed by a predator.  Some can even secrete a noxious and putrid-smelling fluid. 
click on the image for a closer look

Walking sticks are herbivores that enjoy dining on the leaves of deciduous trees   With the exception of the southernmost states - where stick bugs are more prevalent - their populations are relatively low in the United States so damage to trees and plants is limited.  

This stick bug on my window screen is 3 ½ inches in length so based-upon its size I have reason to believe that this is a Northern Walking Stick.  You can learn much more about this cool insect by clicking on this link to the UW-Milwaukee Field Station.