Butterfly Wings are Cool… Literally!

Besides helping butterflies fly, the wings of a butterfly have many different jobs. The colouration can warn predators, attract mates, or provide camouflage. However, one thing you may not be aware of is how butterfly wings are actually complex living organs.

The Problem

Butterflies rely on outside heat sources, such as the sun, to heat up their muscles. This is so that they can flap their wings fast enough to fly. However, since their wings are so thin, they can easily overheat.

Scientists Nanfang Yu and Naomi Pierce wanted to know how insects such as butterflies can keep their bodies warm without overheating. They used a laser to heat up spots on the wings of different butterfly species and found that when the laser reached around 40℃ the insects would respond. They would do things that would stop further heating, such as turning around, flapping its wings, or moving away. These actions still took place when the butterflies were blindfolded, suggesting the heat sensors were on the wings.

A Butterfly’s Solution

As it turns out, butterfly wings have their own living parts. They have veins that transport blood, different sorts of scales, as well as scent pads used by males. These pads are used to release female-attracting pheromones, which release more heat than the surrounding dead scales. In turn, this makes the living areas of the wings much cooler, stopping the wings from overheating.

In addition, studies of living butterflies were conducted on six of the seven butterfly families. They showed that the wings can sense the direction and intensity of sunlight. Butterflies can then respond with specialized behaviours, such as turning away, which can prevent overheating.

For the Future

Yu and Pierce are now carrying out a large-scale study including hundreds of butterfly species. Every time scientists discover new things about a species, it makes me wonder what else we don’t know, and what is left to be discovered.

Written By: Angela Hu