Butterflies

Incredible wing

Over 165,000 species are described, of which 2,780 are found in Sweden. 13% are butterflies and 87% are moths.

Appearance and characteristics

The colors and patterns of the wings can in different species act as camouflage, species recognition or as a warning to attackers that the butterfly is poisonous or bitter. The same goes for the larvae that are often toxic. Many larvae have hairs that are in contact with poison glands. The poison originates from plants that the caterpillar eats. The colors the butterfly wings have can be both pigment colors and structural colors. The structural colors are formed when the incident light is refracted and reflected in different scale layers. This allows the butterfly to shift in shade depending on the position of the wings, to reflect UV-light and to polarize

Butterflies usually have large wings and straw-like mouths but some species have jaws. The largest butterfly is the Atlas moth. It has a wingspan of 30 cm while the smallest, the pygmy moths, only have a 2–3 mm between the wing tips.

Feeding and catching

Butterflies usually have a fluttering and seemingly random flight. This makes them difficult to catch for birds and others who want to eat them. The privet hawk moth and the hummingbird hawk moth can hover when they suck nectar from flowers with their long trunk and then resemble small hummingbirds.

Reproduction

The butterfly female lays her eggs on plants that are suitable food for her offspring. The eggs are 1-2 mm long and round or oval. They usually hatch after 1-4 weeks depending on the ambient temperature. The newly hatched caterpillar begins to eat immediately and gains more than a thousand times its weight before it pupates. The more it can eat the bigger it becomes and so also the resulting butterfly. The larva has eight pairs of feet, all of which have a crown of microscopic hooks that allows it to get a good grip. The skin of the pupa is formed beneath the caterpillar skin, which bursts open and sheds.