Linda's Butterfly page1

Here, in New Zealand, we have only a few butterflies. The most impressive is the Monarch Butterfly (Danaus plexippus), also known as the "milkweed butterfly".

Monarch Life Cycle:

Monarch eggs are placed on the underside of the milkweed plant by a female butterfly. She can lay up to 400 eggs in a day! The eggs are white with a pointed top. It takes about two weeks for the eggs to develop, during which time they change colour, first paling to cream then grey and black as the caterpillar forms inside. Eventually the caterpillar's head is visible through the egg shell.

Caterpillars - A new born caterpillar is only 2 millimetres long. It starts life by eating it's own eggshell. And does not stop eating for three weeks. Each day it can consume it's own weight in food. It eats day and night on milkweed. The toxins in the milkweed make it poisonous to prey, other than wasps and prey mantis. By the time it finishes eating it weighs nearly 3,000 times it's original birth weight, and has shed it's skin seven times!

A caterpillar has spiracles, a ring-like opening which are used for respiration. It has five pairs of large prolegs, and six legs.

When it is ready, the caterpillar starts wandering, looking for a safe place to pupate. It usually climbs to find shelter on the underside of a leaf, a branch of a tree, or the frame of a building. When it finds the right place, it uses a special gland in it's mouth to weave a string of silk to attach itself, by it's tail. It hangs upside down in the shape of a "J". After resting, it begins moving, wriggling until it splits it's skin open for the last time, exposing a soft fleshy layer of pale green. This hardens and turns darker to a jade green, with a ring of gold near the top.

To view a larger version of the pictures below, click once on the picture. Use your back arrow to return to this page.

After two weeks, of being tightly packed inside the chrysalis will appear black. In fact it is transparent, with the black of the butterfly's body showing through. The chrysalis will crack open and the butterfly will emerge. At first, it appears to be all abdomen, with tiny wings. It will cling onto the case of the chrysalis while it pumps fluids from it's abdomen into the wings. The wings will increase in size and the abdomen will decrease. It will then rest while it's wings dry and harden. Monarch Butterflies are aided in this process by the sunlight. On a overcast or cold day, it cannot fully pump or dry it's wings and will become disabled. Once fully able, the butterfly will fly off, looking for a food source.