US scientists have created the first glowing butterfly, by inserting two genes into its DNA that give jellyfish fluorescent properties.
The genetically modified African butterfly glows luminous green in the dark and is part of a project to understand how wing patterns emerge.
Very little is known about the genetic basis for the diversity of colours and patterns seen on butterfly wings.
The research is published in the Royal Society journal Biology Letters.
"It's a way of finding these genes and testing how they evolved," Dr Antonia Monteiro, of the State University of New York (SUNY), told BBC News Online.
The researchers used a technique called germ-line transformation to insert a marker gene that codes for the green fluorescent protein that confers luminosity to jellyfish.
They inserted this marker gene into the eggs of the African butterfly Bicyclus anynana.
This creates mutant butterflies with the fluorescence gene inserted into different parts of their genome. Scientists can study the expression of these mutations when the insects reach maturity.
Researchers have so far been unable to identify any of the mutations in genes that alter colour patterns on butterfly wings.
Dr Monteiro said she thought the particular pattern of Bicyclus anynana, with eye-like shapes on the tips of the wings, was to confuse birds about where its head was.
Birds often attack the heads of butterflies, but if they are fooled into attacking the tips of the wings, the insects clearly stand a better chance of survival.
Dr Monteiro added that she wanted to investigate the environmental factors that led to wing patterns.
"We want to know how the colours and patterns were expressed in those places in the first place."
"It's up to sexual selection, predator interaction, thermoregulation. There're all kinds of environmental factors that eventually determine which pattern is better for the species."