Читать книгу Backyard Bugs - Jaret C. Daniels - Страница 8

Stages of Development

All insects pass through a series of developmental stages as they grow. This transition is known as metamorphosis. Most insects, including butterflies and moths, flies, beetles, and bees and wasps, undergo a complete metamorphosis consisting of four developmental stages: egg, larva, pupa, and adult. The immature stages look much different than the adults, eat entirely different foods, and live in separate environments. Butterflies and moths are good examples. The wormlike larvae have chewing mouthparts; they feed primarily on plant material, live on plants, and have a mostly sedentary lifestyle. The adults have siphoning mouthparts, feed primarily on flower nectar or other liquid resources, and are highly mobile thanks to their wings.

Other insect groups, including grasshoppers, dragonflies and damselflies, true bugs, and cockroaches, undergo incomplete metamorphosis. This process consists of three developmental stages: egg, nymph, and adult. The young nymphs often closely resemble the adults in appearance, although they are smaller in size. They also may share the same environment and food resources that adults frequent, and they often behave similarly. True bugs are a good example. The nymphs are essentially smaller versions of the adults. They have piercing-sucking mouthparts, feed on plant sap, live primarily on plant material, and typically move by walking. The resulting adults differ in that they are larger, reproductively active, and have wings, enabling flight.