BUTTERFLIES & MOTHS

Lepidoptera

Lepidoptera is a massive and diverse group of insects found on almost every continent on earth. The wings of a Lepidopteran are extremely delicate and thin. Butterfly wings rest vertically, while moth wings hang down, cloaking the body. The antennae differ between butterflies and moths. Butterflies have long, clubbed antennae, while a moth’s are thin and feathery. Both have a proboscis (tongue) that uncurls to feed on the nectar of flowers. Moths are nocturnal unlike butterflies that rest in the day.

The life cycle of a Lepidopteran is very long and complex. The female lays a nest of about 100-200 eggs, each of which are less than 2 Mm long. In most species, the bottom is glued to the leaf with a rapidly hardening substance. After a few weeks (time varying in species) the eggs hatch into larvae or Caterpillars. The larvae immediately start eating the shell of the egg. They spend the next few weeks of their lives eating leaves (in some species other arthropods) and moulting their outer skin. Many species have a brightly colored “horn” that extends to frighten off predators. After fully grown the caterpillar crawls onto the underside of a leaf and hangs upside down. The caterpillar, forms a chrysalis around itself. Some species form another layer, called a cocoon, around the chrysalis. Inside the chrysalis the caterpillar changes into an adult. After about 1-2 weeks the fully grown insect emerges. The wings are naturally crumpled at first. The insect stands in the sun to let them dry while the heart pumps blood to unfold them. The adult Lepidopteran is ready to fly.

The wings of a Lepidopteran are extremely unique. The wings are covered in soft scales and are built up of millions of fibers, each one only a few microns across. The collage below shows Lepidopteran wings under a Scanning Electron Microscope.

Some of these insects undergo vast and dangerous migrations across the continent. The most spectacular of these is the Monarch Butterfly (Danaus plexippus) migration. The butterflies swarm in the millions over the country, traveling thousands of miles across the continent to shelter from the harsh winters. It is unknown how they all find their way to these locations. The butterflies hibernate in the millions on the branches of trees.