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Grade 3, Unit 4, Reading in the Content Area

The Life Cycle of the Butterfly

Insects and butterflies are the most common type of living things on Earth Both butterflies and moths belong to the family of insects called Lepidoptera. Butterflies exist all over the world with thousands of different variations. In the United States and Canada, there are more than 700 types of butterflies. Butterflies go through specific stages of development. The following chart shows them:

Stage Egg Larva Pupa Adult

Let's look at the stages one-by-one.

Name Egg Caterpillar Chrysalis Butterfly

THE EGG: A butterfly starts its life as an egg. The female butterfly lays many eggs, and each egg can hatch later into a caterpillar. Eggs laid in the spring or summer usually hatch in a few days, but those laid in the fall may not hatch until the following spring. Eggs of Lepidoptera vary greatly in size and shape, and while many are shaped like a ball, some may be flattened. The eggs are usually smooth, but some may have ribs, pits, grooves or fine ridges. Each egg has a small hole through which it is fertilized. An adult female lays eggs singly, in small clusters, or as an egg mass (Note: Painted Lady Butterflies most often lay single eggs). Frequently, eggs are deposited on a plant that will serve as food for the larvae, the next stage of development. The larva eats its way out of the egg casing and sometimes also eats the eggshell.

(Diagram of an egg. The actual size is about the size of the head of a pin.)

THE LARVA: From the egg, a larva or caterpillar will hatch. Just as every type of butterfly has a different color and pattern, each type of caterpillar is different. Caterpillars eat a great deal, some eating twenty times their own weight in food. To allow for growth, caterpillars shed their skin three to four times. Their power to move comes from the

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4000 muscles they have (humans, by comparison, have only 640 muscles). The parts of a caterpillar (shown in the diagram) are: ! Head: Contains eyes, antennae and mouth parts, other sensory organs and feeding mechanism; spinnerets used to spin silk are tiny pegs located under the mouth. ! True legs: Front legs (clasping, stay throughout all stages). ! Prolegs: Back legs (suction cups for gripping, not visible on adult). ! Spiracles: Breathing holes for respiration. ! Setae: Bristles (hair, protection against changes in the environment).

Abdomen

Bristles (Setae) Thorax

Head

True legs Segment Spiracle

Prolegs

Anywhere from eight to ten days (to over a year, depending on the type and time of the year eggs are laid) after a caterpillar hatches, it will attach itself to a leaf or a stem. (In the case of the Painted Lady Butterflies that we studied, they will attach themselves to the lid of a plastic jar.) When the caterpillar positions itself on the lid into a "J"-like position, it should not be disturbed. This tells us that it is getting ready to go into the next stage, to form the chrysalis (pupa). The chrysalis is the thin case that encloses the pupa.

Caterpillar in "J"-like position on lid of a jar.

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Grade 3, Unit 4, Reading in the Content Area

THE PUPA: The caterpillar will shed its skin several times. After the last shedding of the caterpillar, a soft pupa is formed underneath the skin. Inside the pupa, a butterfly is being formed. Before the butterfly comes out from the pupa, the case or chrysalis splits open and the butterfly slowly pushes its way out. The amazing way in which an egg changes to a larva, then to a pupa, and finally to an adult butterfly, is called metamorphosis.

The Chrysalis

THE ADULT: The final stage of the butterfly, where it looks most like an insect, is called the adult stage. A butterfly's body has three parts: the head, a middle part called the thorax and an abdomen. It has six legs. The two front legs are usually smaller than the other four. Two feelers called antennae, are attached to the butterfly's head. A butterfly uses its antennae to touch, feel and smell. Most butterflies fly by day and in the evening they hide and rest. The following illustration is of the typical butterfly. Its parts are as follows:

! ! ! ! ! !

Thorax: Located behind the head. The wings join into the thorax. Abdomen: Long part of the body, behind the wings. Antennae: Structures used to feel and smell. Feet: Used to hook onto things, provide motion, and to taste. Proboscis: A tube used for drinking nectar from a flower. Head: The top part of the insect containing sensory organs and feeding mechanisms.

Wings

The Adult Butterfly

Antennae Veins Head Proboscis (feeding tube) Legs 109 Abdomen

Thorax

Grade 3, Unit 4, Reading in the Content Area

A butterfly drinks the sweet juice called nectar, from flowers. A butterfly's mouth has a long tube called a proboscis, that is used to pull the nectar from the flower. When a butterfly is not using this tube, it is rolled up under its head. Each type of butterfly has its own distinct colors and patterns. The wing colors are made up of tiny little scales, a little bit like the scales on a fish. If you touch a butterfly's wings, some scales will come off on your finger, and you will be able to see the color. Butterflies are measured from the tip of one wing to the tip of the other wing. This is called the wingspan. Many butterflies fly south in the fall. They spend the winter in warm places and in the spring, they fly north again. Butterflies are valuable not only because of their beauty, but also because they help to bring pollen from flower to flower. This is required for flowers to form seeds so that new flowers can grow. The Difference Between Butterflies and Moths: Generally the bodies of moths are more plump and furry than those of butterflies. When they are resting, moths hold their wings flat or fold them over their backs. Often feathery, their antennae vary in structure but do not have the "club-like" appearance found at the end of a butterfly's antennae. Most moths hide during the day and fly at night and they are attracted to bright lights. Unlike butterflies, the larvae of moths spin silken cocoons after the larval stage.

Moth

Butterfly

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Grade 3, Unit 4, Reading in the Content Area

Name _______________________________

Date ___________________

Think about and answer the following questions: 1. Describe the stages in the life cycle of a butterfly. ___________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ 2. How is the life cycle of a butterfly different from the life cycle of a human being? _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ 3. What body parts are the same in the larva form (caterpillar) and the adult (butterfly)? _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ 4. Pick a body part of the adult butterfly and explain its function. _________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________

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