Imagine if your life was trying to imitate a stick, well here is a garden critter who was caught out and needed re-location to where he’s far less obvious. These are the longest insect in the world and are expert at moving and looking like sticks.
The Phasmatodea (sometimes called Phasmida or Phasmatoptera) are an order of insects, whose members are variously known as stick insects (in Europe and Australasia), walking sticks or stick-bugs (in the United States and Canada), phasmids, ghost insects and leaf insects (generally the family Phylliidae). The ordinal name is derived from the Ancient Greek φάσμα phasma, meaning an apparition or phantom, and refers to the resemblance of many species to sticks or leaves. Their natural camouflage can make them extremely difficult to spot. Phasmatodea can be found all over the world in warmer zones, especially the tropics and subtropics. The greatest diversity is found in Southeast Asia and South America, followed by Australia. Phasmids also have a considerable presence in the continental United States, mainly in the Southeast.
Phasmatodea species exhibit mechanisms for defense from predators that both prevent an attack from happening in the first place (primary defense) and are deployed after an attack has been initiated (secondary defense). The defense mechanism most readily identifiable with Phasmatodea is camouflage, in the form of plant mimicry. Most phasmids are known for effectively replicating the forms of sticks and leaves, and the bodies of some species (such as Orxines macklotti and Palophus centaurus) are covered in mossy or lichenous outgrowths that supplement their disguise. Some species have the ability to change color as their surroundings shift (Bostra scabrinota, Timema californica). In a further behavioral adaptation to supplement crypsis, a number of species perform a rocking motion where the body is swayed from side to side; this is thought to mimic the movement of leaves or twigs swaying in the breeze. Another method by which stick insects avoid predation and resemble twigs is by feigning death (thanatosis), where the insect enters a motionless state that can be maintained for a long period. The nocturnal feeding habits of adults also help Phasmatodea to remain concealed from predators.
Web Links :
http://en.wikipedia.org/wiki/Phasmatodea