Key points
Gainesville, Fla. --- Have you ever thought about reinventing yourself? According to a new study on moths conducted by Andrei Sourakov, collection coordinator of Lepidoptera at the Florida Museum of Natural History and affiliate associate professor of entomology at the University of Florida, it’s not as hard as you might think.
Sourakov specifically looked at wing development in luna ( Actias luna ) and polyphemus ( Antheraea polyphemus ) moths. By adding a small amount of heparin and dextran sulfate — two types of sulfated polysaccharides — during crucial stages in their development, he was able to drastically alter the patterns on their wings. The patterns of luna moth wings in particular changed from a cryptic (camouflaged) coloration to one that was aposematic (conspicuous).
Both compounds also changed the shape of luna moth wings, something never before experimentally achieved in Lepidoptera, the group that encompasses all moths and butterflies.
“Some giant silk moths have eyespots that make them appear threatening to would-be predators. Others look like leaves, with translucent eyespots resembling holes to make it more convincing. What’s amazing to me, and what I learned from this study, is how easy it is for these features to go from one state to another. They do this without big inventions by simply expanding or contracting existing elements to the point where eyespots look completely different. All they need is a slight increase in the amount of certain compounds at the right moment,” Sourakov said.
New study builds on previous work
Moth and butterfly eyespots are located in different parts of the wing, indicating they evolved independently of each other.
Initially, Sourakov wanted to know whether these two groups used the same genes to create eyespots or if they independently converged on the same design. To find out, he induced the gaudy color and pattern changes on their wings by adding sulfated polysaccharides to several giant silk moth species.
The addition of external heparin and dextran sulfate augments the activity of a group of proteins called wnt. Sourakov hypothesized that if the eyespots of two different species reacted similarly to heparin and dextran sulfate, it’s likely they’d be homologous (have the same evolutionary origins), though further experimental work would be needed to confirm that this was true.
In the largest family of butterflies, called nymphalids, eyespots are located along the wing margin. The addition of heparin during the early development of nymphalids can delete their eyespots entirely.
But when Sourakov administered heparin to two species of giant silk moth in a previous study, their eyespots got bigger . To Sourakov, these reversed effects were a clear indication that eyespots of these moths evolved independently of those in butterflies.
After his initial studies on giant silk moths were published in 2020, Sourakov decided to add another, very different-looking species – the luna moth, which is famed not for its eyespots, which are barely noticeable, but for its long hindwing tails.
Experiments induced change to Lepidoptera wing shape and a rapid shift from cryptic to aposematic patterns
This new study, recently published in the journal Evolution & Development, took Sourakov a total of seven years to complete, during which time he hand-reared more than 700 luna and polyphemus moths from egg to adulthood.
Sourakov administered tiny quantities of heparin shortly before and after pupation, the stage in which insect larvae undergo their final metamorphosis into adults and when their wing patterns are determined.
But after two years of trial and error, nothing happened. Undaunted, Sourakov continued altering the concentration of heparin and the times at which doses were administered.
“I kept trying, and eventually, I achieved a single transformation. But it wasn’t of the wing pattern. It was the wing shape. This single specimen was so different that I couldn’t ignore it,” he said.
The specimen was a luna moth, and the change Sourakov observed was to the shape of its wing tails, which grew wider than in all of the moths he had reared up to that point. Scientists think luna moths evolved these tails as a means of deflecting bat attacks away from the main part of their bodies. As to why the eyespots remained the same while the tails grew wider, Sourakov was stumped.
“I thought, this is very bizarre. Maybe the genes that are normally responsible for wing patterns are here responsible for wing shape, because that’s seemingly the only thing that was transformed.”
Sourakov soon debunked this idea by adjusting the timing of when heparin was administered, which finally yielded the anticipated eyespot alterations combined with wing shape changes.
In polyphemus moths, the yellow borders of the two upper lemon-shaped eyespots thickened, and the surrounding brown scales that matched the rest of the wing became whiter. The black border surrounding the hindwing eyespots also expanded. Both changes made the eyespots more conspicuous.
In luna moths, the circular eyespots on the posterior wings became squinted and developed a thick border of mascara, similarly making them more noticeable.
The ability to change their appearance within a short time span allows moths to rapidly adapt to new environments. Luna moths, for example, stay hidden from visually oriented predators by having the general appearance of a leaf. If their cryptic leaf disguise suddenly stopped working, mutations combined with hunting pressure from birds could quickly increase the visibility of their eyespots within just a few generations.
“If you are a smaller bird or a squirrel, you will think twice before attacking something in the darkness of the forest that looks like the eyes of an owl. Butterflies and moths are masters of such deceptions,” Sourakov said.
Wing tails bend the cookie cutter out of shape
The reason why wing shape was also affected, however, remains unclear, and especially puzzling is why it has not been observed in butterflies. Sourakov has a few ideas.
One theory has to do with how moth and butterfly wings ‘know’ when to stop growing. Lepidoptera wings are unique in having what is referred to as a cookie-cutter form of growth. Unlike the wings of other flying insects, which simply stop growing when they reach a certain size, the growth of Lepidoptera wings is terminated by a series of programmed cell deaths along what will ultimately become the wing margins, giving them unique shapes.
The signal for these cells to self-destruct is mediated by a protein called cut, which does not respond to heparin or dextran sulfate.
But earlier in the process of development, before the marginal cells die, another type of signaling protein called wingless that does respond to heparin and dextran sulfate has been shown to control the size of individual elements within the wing, defined as the space between veins.
The wingless gene is mostly inactive by the time eyespots begin to form, which is when Sourakov begins to tamper with wing development. Changes to the size of elements are thus seldom observed when the focus of an experiment is on eyespots.
But wingless also has an important function in repairing damaged cells after a wing sustains an injury, meaning it can be turned on and off when needed. Sometimes that need is to grow new cells in wounded areas of the wing. Sometimes, as is the case with pipevine swallowtails, that need is to develop its tiny wing tails.
A landmark study published in 2010 demonstrated that both cut and wingless are active in the tail-formation of pipevine swallowtails. Sourakov suspects the same may be true of luna moths. If this is correct, it would mean that the wingless gene was independently co-opted by natural selection for the evolution of wing tails in moths and butterflies. But compared to the tiny wing tails of the pipevine swallowtails, which function as visual distraction for birds by adding to a false head effect , the luna moth tails are much longer, and their shape affects the way these insects fly.
“This is just my deduction, but I think it is very plausible and would explain why in butterflies or other moths we don’t see much change to the wing shape in response to heparin– wingless is not turning on at that stage of wing development in most species,” Sourakov said.
Evolution & Development
Wing Shape and Color Pattern Modifications in Giant Silk Moths Using Sulfated Polysaccharides: Understanding Morphogenic Signals in Pupal Wings of Lepidoptera
21-Aug-2026