Butterfly Stages Butterfly eggs have a hard outer shell. This protects the larva inside. The shell is called the chorion. Inside, the egg is lined with wax. This keeps the egg from drying out. Not all eggs are the same shape or size. Larva have three body parts-head, thorax and abdomen. Even though the caterpillar has 6 eyes, it can't see very well. The antennae help guide the larva. They breathe through holes in the side of their bodies. Larva have a set of real legs and five false legs called prolegs.
Butterfly Stages cont. As the larva pupates, it splits the exoskeleton and the larval skin comes off. When the skin is part of the way off, the cremaster appears. It is a spiny part at the end of the abdomen that the baby butterfly hangs from until it is strong enough to fly. The adult butterfly has three body parts-head, thorax and abdomen. It also has 6 legs but it curls up the front ones so sometimes people think there are only four. Butterflies have a proboscis which is a long straw-like tonque which it can use to suck up nectar and water. There are two sets of wings-hindwings and forewings.