Butterflies - General Information

Butterflies and Moths belong to the group of insects called Lepidoptera. Like other insects they have a head, thorax, abdomen, two antennae and six legs. They also have their skeleton on the outside of their body, a feature which conserves moisture. Additionally butterflies and moths have four wings and a coiled proboscis for drinking nectar from flowers. There are about 20,000 species of butterfly in the world and about 10 times as many species of moth. Australia has about 400 species of butterfly, mostly in the tropics. At Bushy Park Wetlands we are lucky to have 20 species of butterfly and many more species of moth. This article won't go into detail on moths, except to point out the main difference between butterflies and moths.
Butterflies Active during in the day. Most have slender, hairless bodies. Rest with wings closed above their body. Antennae, like thread with a knot at the end. Are usually brightly coloured. Caterpillar stage form a hardened chrysalis. Caterpillars do not spin silk.	Moths Active during dusk and the night. Most have plump, furry bodies. Rest with wings flat beside their body. Antennae look like feathers. Are usually dull colours. Caterpillar stage form a soft cocoon. Caterpillars do spin silk.
Metamorphosis - The Life Cycle of a Butterfly
Egg Stage: The female butterfly lays her eggs on plants which will provide the offspring with a source of food. Depending on the species, she may lay from a dozen to a hundred eggs which range in size from a pin head to 2mm across. A sticky substance deposited with the eggs holds them to the plant. Hatching can take a week or may take a few months.
	Caterpillar or Larvae Stage: After hatching from the egg the 14-segment lava starts eating. The caterpillar spends most of its 2 weeks of life at this stage eating and usually consumes more that its body weight every day. As the caterpillar grows it sheds its skin and after four or five moultings, the skin removed reveals the chrysalis or pupa. Some caterpillars spin a cocoon first but many just fasten themselves to a plant.
Pupa or Chrysalis Stage: Depending on species, the pupa period lasts from a week to nearly a year. Most species spend the winter as pupa and emerge as butterflies in spring or summer. Although the Chrysalis looks lifeless, there's a lot going on inside as the caterpillar is literally liquefied and then reassembled to form the new solid structures of the butterfly.
	Butterfly Stage: This is the stage that most of us are likely to see. The first evidence that a butterfly is about to emerge is usually a transparency of the chrysalis shell, revealing colours beneath. The thorax swells and cracks the chrysalis and within a few minutes, a limp, damp butterfly emerges. Initially, the wings are like soggy paper, but pumping blood and using gravity causes them to expand. A little warming in the sun for an hour and the butterfly is ready to fly off to feed. Most butterflies feed only on nectar which provides energy but does not contain life supporting proteins. On average butterflies only live about two to three weeks.
More Information about Butterflies: Butterfly's wings are covered with scales that overlap to provide colour and beautiful patterns. The patterns on the top and bottom of their wings are usually different and sometimes differ between male and female. Males are identified by a slit at the tip of the abdomen, while females have a round hole where the eggs are laid. The antennae are organs of smell used to locate food and a mate. Butterflies have 3 pair of feet and each leg has a hairy pad which is used as a taste organ. Butterflies use their proboscis to suck up liquid to maintain their water balance and energy stores. As they fly from flower to flower feeding on nectar, pollen grains clinging to the body are exchanged which helps plant pollination. Butterflies have a heart that runs the length of its upper body. Butterflies are cold-blooded and seek shelter in cold and wet weather. They cannot fly if their body temperature falls below 30°C. Butterflies always have their eyes open and do not sleep. In most case the male dies soon after mating and the female dies soon after laying her eggs.
20 Butterflies at B.P.W. - Pictures from Museum of Victoria.