Butterflies and moths belong to the insect order Lepidoptera, which means scaly-winged. These scales give butterflies their colour and moths their camouflage. For the most part, moths are nocturnal while butterflies are diurnal. The Lepidoptera are holometabolous insects which means they have complete life cycles comprising egg, larval, pupal and adult stages. They have four wings, two coupled pairs. Some species have secondarily lost their scales and have transparent wings, but most are scaled.
Larval ‘leps’ are called caterpillars and they are eating machines. They walk about on a variable number of legs and have chewing mouthparts to consume leaves and other plant parts. Caterpillars are often so different from the adult forms that only a small proportion of the world’s species have been identified and described. Most species are known only from their adult forms. Many caterpillars are economically important pests of gardens and food crops, forests, orchards and stored foods. A few are quite useful, like the silk-wormss (caterpillars of the families Bomycidae and Saturniidae).
When they have grown enough, the caterpillars pupate, rearranging their bodies inside the chrysalis and using all that larval energy to make a moth or a butterfly, capable of flight. This is the dispersal and reproductive stage of life and some adults do not even have functional mouthparts. Those that do have a long sucking apparatus which for the most part is unrolled to sip up the nectar of flowers. Both caterpillars and adult forms are usually fairly specific in their feeding habits, requiring a particular type of plant or group of plants for their survival.
The coloration of butterflies and moths has several purposes. The bright colours of butterflies are signals for sexual activity or a message to predators that they are inedible. For moths, their colouration allows them to blend into a background during the day when they are resting. When they come out at night, they use pheromones to attract mates and their fuzzy antennae to find food, instead of sight. Many leps have eyespots on their wings, circular marks designed to make predators think they are dangerous predators instead of tasty prey. Other moths and butterflies mimic poisonous or otherwise inedible species. Some butterflies, for instance, can eat poisonous plants and then use those poisons to make themselves inedible. They advertise this with bright warning colours. Other species will then mimic them to gain the same protection even though they are not poisonous.
There are so many families of lepidoptera that it is impossible to deal with them here at anything more than a superficial level. Butterfly families include the swallowtails, milkweeds, brush-footed butterflies, gossamer-winged butterflies, skippers, fritillaries, heliconians, snout butterflies and admirals. Moth families include the hawk moths, silkworm and royal moths, tiger moths, gypsy moths, hooktip moths, flannel moths, snout and plume moths, carpenter moths, and many more smaller, lesser known families.
Balanced against the damage done by caterpillars is the joy that these beautiful creatures give us when they flutter by us on a bright summer’s day or warm summer’s eve. They are natural works of art and deserve our respect and protection. Many species are endangered by our overuse of pesticides while others are being lost due to deforestation of tropical rainforests. Manmade extinction is forever and only we can stop it.
References: A Watson, P Whalley 1983. The Dictionary of Butterflies and Moths in Colour. Borror and Delong 1971 An Introduction to the Study of Insects.
