Moths: Wings Are For More Than Flying

Neatly ordered scales provide an excellent sense of symmetry. Taken from:

If anyone has ever seen (or squashed) a moth, they’ve probably noticed the powdery residue that comes off them. What many people don’t understand is that that residue isn’t a powder. They’re scales…Yes, scales. The moth’s family nomenclature is Lepidoptera, which means “scale wing”. Why would moths have scales on the device that they primarily use to fly?

The scales provide multiple uses, including assistance to flight. With regards to flight, the scales, since they’re an addition to the wings, provide extra lift, since air is trapped in between the wing and scales. But there is also a defensive reason. These scales protect the moths from being trapped in spider’s webs, since the scale is what attaches to the web, and not the wing. Those scales also aid moths in “evasive flight”, a defensive mechanism that assists the moths in escaping from birds that don’t fly precisely. Since birds are attracted to colors, which the scales often have, the bird will naturally find the moth interesting. Sometimes though, the scales warn the bird, who, by prior knowledge, knows that the moths are not good to eat. However, for those that are good to eat, the moths have devised flying techniques to not only escape the birds, but also guard itself through camouflage when the bird is looking for it. This flight pattern is noticeable in butterflies as well, which makes some researchers think that butterflies evolved from moths.

Camouflaged Moth. Taken From jimmccormac.blogspot

These are the well organized scales of a moth. Taken from

Interestingly enough, one species of moth is dubbed “Hummingbird” due to it being able to hover while it feeds on nectar. This video shows an example of their flight. As shown, these moths are extremely precise. The scales play a role here too, even though the moth doesn’t know it. When they’re on trees or flowers, their scales pick up the pollen or small seeds that the plant gives off. Since it flaps its wings quickly, the pollen that is lodged into the scales will be dislodged somewhere else while the moth is on its way.

The practical use for engineering with this is quite clear. Not only could we observe the insects in their environments, but also help plant-life through pollination – a new breed a field work. Also, by using the flying patterns of the moth, we can change the structure and defense of other mechanical flyers. Perhaps, that will grant less interference when studying. We can also adopt the scale-flight method on our flying machines to make lifting into the air easier. Whether one, the other or both, advancements in one type of machine will benefit all of them.


  1. The Powder of a Moth’s Scales
  2. Scales: On the Wings of Butterflies and Moths

One Comment

Lorena Barba posted on November 4, 2012 at 5:06 pm

I am not sure that there is evidence supporting the idea that scales add lift. Your second source mentions this as a hypothesis only, and then goes on to talk about the many other uses of scales.

I am more receptive to the idea that they reduce drag (like in sharks), but that they assist in flight? hmmm …