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In nature there is a constant war being waged by the strong on the weak. Those insects that belong to the weaker class are not powerful enough to fight back, so they must outwit their enemies in other ways. A small group of insects, mainly the bees and the wasps, can well protect themselves by stinging a would-be foe, and others emit pungent odors or have irritating spines or hairs; but in the majority of cases the most widely used means of protection employed by insects is that of remaining unseen. This does not necessarily mean that the insect, wishing to hide, shuts itself away from the outside world. So closely do some insects resemble their surroundings that they can live in the very midst of their enemies and still not be recognized. This ability is sometimes called protective coloration.
The common walking-stick is a good example of an insect that looks so much like the twigs upon which it lives that it takes a sharp-eyed bird to see where the insect stops and the twig begins. The walking-stick has a slender body, from two to three inches in length. It is wingless and has three pairs of legs. When at rest it holds the first two legs directly in front of its body to complete the illusion of looking like a small stem. When the walking- stick is young, it is green in color. As it grows older it changes to brown, and so, by selecting brown twigs or fresh green ones as resting places, easily escapes detection because it looks so much like a twig itself. It feeds greedily on leaves and is sometimes harmful to walnut and other trees.
The ability of the walking-stick to look like something other than itself is possessed by other insects also. Measuring worms look like twigs; mourning-cloak butterflies resemble dead leaves; certain kinds of moths have the appearance of bark, while some tree hoppers imitate thorns.
One type of insect, found in the islands of the Indian Ocean, looks like a leaf and is called a "leaf insect." It is usually bright green in color and measures about three inches in length. Its foliage-like appearance is due to the broad, ribbed wings and to the leaflike expansion at the joints of the legs. Even the eggs bear a curious similarity to the seeds of plants. Leaf insects are found at the tips of leafy branches, and because of their form and color are not readily discovered. They feed upon leaves at night and are usually quiet during the day. They are members of the same family as the walking-stick.
The praying mantis that lives in this part of the country is colored green, especially when young, and, like the walking-stick, mimics the twigs upon which it lives. Some species living in the tropical countries are brightly colored and resemble flowers. By sitting among the flowers that they have taken as a model, they attract insects and devour them. What a clever trapper the praying mantis is!
Birds that eat insects soon learn to recognize the bad-tasting ones by size, form, and especially color, and so leave them alone. It often happens that edible insects look like some of the insects that are bad tasting and in this way escape being eaten. Such a relationship has been established by the viceroy butterfly for the monarch butterfly. The monarch, or common milkweed butterfly, has a bitter flavor and is carefully avoided by the birds. On the other hand the viceroy, which has no bitter taste and is not even closely related to the monarch, resembles the monarch so much that birds will also refuse to eat it. Perhaps they leave the viceroy alone because they mistake it for the monarch.
This imitation of one insect by another for protection is known as mimicry. Numerous defenseless moths and flies are colored so much like stinging bees and wasps that they are, no doubt, commonly avoided by their natural enemies. These mimics take advantage of the distaste which their enemies have connected with the yellow and black appearance of bees and wasps, and with these "sham warnings" have a better chance of escape. Grove
After you read about insect coloration
Read How to Avoid Being Eaten
by naturalistoutreach.
Read How to Avoid Being Eaten
by naturalistoutreach.
Craft Tiny Insects to Enhance The Lesson About Insects:
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