Tony Romano, age 10, of Bountiful, Utah, for his question:
DO ALL CATERPILLARS TURN INTO BUTTERFLIES?
Some caterpillars have glands that secrete unpleasantsmelling fluids, and others have a sickening taste. These are some of the devices that save lots of caterpillars from being eaten by animals and birds. False eyespots can be found on others which frighten away attackers. And for defense, some caterpillars have long whiplike appendages on their backs as means of defense.
Despite having many defense mechanisms, few caterpillars ever reach the adult stage. Birds and larger animals eat them, and many are killed when parasites burrow into their bodies.
A caterpillar is a wormlike creature that is the second or larval stage in the life history of both the moth and the butterfly.
Shortly after a butterfly egg hatches, the tiny caterpillar that is born crawls out and begins to eat. Caterpillars are heavy eaters. The butterfly or moth does all his growing during the caterpillar stage. The larva stores up the tissues that later are transformed into the adult insect. The adult grows no more after it grows wings.
The caterpillar grows but his skin does not. Soon, with time, the skin becomes too tight and the caterpillar prepares to throw it away. A split starts on the upper part, near the head, and the caterpillar wiggles out. The creature is then covered in a new, soft skin which formed under the old one. In a few days this one, too, is outgrown and the process of sluffing off the skin is repeated.
In warm regions most species stay in the caterpillar stage from two to four weeks. In cold countries some species take from two to three years to pass from the egg to the butterfly.
Most caterpillars have 12 rings or segments, not including the head. To each of the first three segments is fastened a pair of five jointed legs. These develop later into the legs of the adult insect. The prolegs on the abdomen are not really legs and are shed with the last skin. Sometimes, as with the so called measuring worms, there are two pairs of prolegs on the abdomen, and the larva moves by drawing these hind legs up to the front pair.
A caterpillar's head has six simple eyes on each side. It guides itself by a pair of short, jointed feelers. Strong, biting jaws differ from the butterfly's sucking mouth. The body can be either naked or covered with spines or hairs. ,
Sometimes, in years when caterpillars are numerous, fields are made bare of plants and even trees are stripped of their leaves. The cabbage worm, the cotton worm, the army worm and cutworms are especially troublesome.
In most years, however, the balance of nature decides that most caterpillars become food for birds and animals. Only a very limited number can make it to the air as moths and butterflies.