In New Zealand there are 22 species of butterfly and over 1,700 species of moth. Eleven of these 22 butterfly species are found only in New Zealand. Some of the others originally came from overseas and are now resident here. Others occasionally arrive here, usually from Australia, on wind currents. Towns on New Zealand’s west coast, such as Whanganui, are often host to these wind-blown species.
World-wide, there are about 17,500 species of butterfly and around 160,000 species of moth. They form a significant portion of world fauna. Butterflies and moths are from the insect order called Lepidoptera. The name comes from the Greek words lepido which means “scale” and pteron which means “wing”. The scales on Lepidoptera wings give them their colours and patterns.
Like other insects, Lepidoptera have three body parts (the head, thorax and abdomen) and the adults have two pairs of wings (one pair of forewings and one pair of hindwings). They also have a pair of feelers (antennae) on their head and six legs joined to their thorax. We can tell species of Lepidoptera apart by the patterns on their wings, wing shape and leg shape.
There are several basic differences between moths and butterflies. Moth antennae are usually feathery or pointed and butterfly antennae are usually clubbed. Moths tend to fly at night and butterflies tend to fly during the day. Moths usually rest with their wings flat and butterflies rest with their wings closed upward. Moth abdomens are usually plump and butterfly abdomens are usually slender.
There are four stages in a Lepidoptera life cycle. Egg, caterpillar (larva), cocoon (pupa) and adult moth. Caterpillars look different to adult moths. While they eat and grow, they will shed their skin (moult) several times. Eventually, the caterpillar will build a cocoon around itself. While inside its cocoon the caterpillar will undergo metamorphosis and emerge from the cocoon as a moth or butterfly.
There are advantages in being a Lepidoptera. Larval insects which are different to the adults can occupy different niches from the adults. This avoids competition for resources between the young and adults of a species. In addition, winged insects can travel greater distances than similar insects which do not have wings. This allows them to access the resources of more distant areas and increases their feeding and breeding ranges.
Collecting insects, especially butterflies, was a popular hobby from the late eighteenth century to the mid twentieth century, and is still enjoyed by many people today. As we learn more about the relationships between living things, we are discovering the unique role each plant and animal plays in its ecosystem and the wider natural world. The removal of one species from the ecosystem will have an effect on the remaining species. Because of this, many naturalists now collect photographs of plants and animals, including butterflies and moths, rather than collecting actual specimens of a species.
Lepidoptera have a strong presence within cultural history and art, providing a wealth of colour, shape and activity to our surroundings. They have often been used to decorate both every-day and special objects. References to Lepidoptera in poetry, fables, fairy tales, dance and theatre abound. Butterflies often seem to be the the goodies while moths are sometimes depicted as baddies or just plain foolish.
Metamorphosis has always been the greatest symbol of change for poets and artists. Imagine that you could be a caterpillar one moment and a butterfly the next. Louie Schwartzberg, 2014.
Moth: I gave you my life. Flame: I allowed you to kiss me. Hazrat Inayat Khan (1882-1927).
Libby Sharpe is the senior curator at Whanganui Regional Museum.