| Color is not the only way to hide: taking on the actual shape and texture of a leaf or twig is sometimes a much more effective type of camouflage. Stick insects of the tropical cloudforest, and inchworms in temperate regions both bear a convincing resemblance to twigs. Geometrid moths have the colors, shapes, and patterns of dead leaves, and are virtually invisible when they land on fallen leaves on the tropical forest floor. For this appearance, however, they sacrifice an aerodynamic wing shape. The huge investment they have made in this camouflage indicates that they must be a very desirable prey indeed. |
The flattened, spiny shape of this insect is typical of "stick" and "leaf" insects which attempt to mimic the shapes of
natural vegetation. Photo credit Corel Photo Clipart CD.
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When approached by a predator, the worst thing a camouflaged insect can do is move. If disturbed, the geometrid moths, stick insects and many other hidden insects will attempt to remain motionless. A sudden movement would call attention to them, and destroy their resemblance to an inanimate object. For this reason, many camouflaged insects are nocturnal, moving only during the night when they can't be easily seen. |
| When these insects are forced to move, they try to be inconspicuous about it. A stick insect will step away rather grudgingly when disturbed, rocking back and forth as it does so, to give the impression of a twig moving in the wind. The moths that imitate dead leaves will let go of a branch and simply fall gradually to the forest floor, in the same way that a true dead leaf would. |
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[tropical forests] [insects] [leaves]
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