Warmer Climate May Cause Male Dragonflies to Lose Their Patchy Wings
Dark spots on the insect’s wings can cause them to overheat. But as they lose them to adapt to climate change, potential mates may not recognize them
Male dragonflies may lose their wing pigments to adapt to a changing climate, according to a new study published this month in Proceedings of the National Academy of Sciences. While males are losing their wing bling, female dragonflies are not.
If male dragonflies lose their signature wing patterns, female dragonflies may have a harder time identifying a potential mate, reports Sofia Quaglia for the Guardian.
"Our research shows that males and females of these dragonfly species are going to shift in pretty different ways as the climate changes," study author Michael Moore, an evolutionary biologist at Washington University in St. Louis, tells CNN's Rachel Ramirez. "These changes are going to happen likely on a much faster timescale than the evolutionary changes in these species have ever occurred before."
Globally, about 3,000 species of dragonflies live in freshwater habitats. Each species has a unique color along their bodies or wings that helps them camouflage into their surroundings, attract mates, intimidate rivals and ward off predators. Some dragonflies—such as the twelve-spotted skimmer, the widow skimmer, or the common whitetail—have unique dark, patchy wing colorations,.
The black pigmentation patterns on the wings can potentially raise a dragonfly's body temperature by 2 degrees Celsius or 3.6 degrees Fahrenheit, the Guardian reports. Dragonflies are cold-blooded, meaning they can't regulate their body temperatures like mammals and birds can. The rise in body temperature can damage their wing tissues, reduce their territorial fighting abilities and even cause death from overheating. More melanin on the insects' wings can be compared to wearing a black T-shirt on a hot day, CNN reports.
Moore and his team examined more than 300 North American dragonfly species and compared them to the wing colors of 2,700 dragonflies of varying species from different locations using the citizen science database iNaturalist, reports Christa Lesté-Lasserre for New Scientist. The analysis found dragonflies in warmer climates tended to have less pigment on their wings than other dragonflies living in cooler temperatures with darker, more elaborate wing decorations, the Guardian reports.
Using data from iNaturalist, the researchers also found male dragonflies had less coloration on their wings in the hottest years from 2005 to 2019. In cooler years, the dragonflies had more colorful wings, implying that less colorful male predatory insects will survive in hotter climates, per New Scientist.
However, females are not showing shifts in their wing color as males are. The pigments on insect's wings are species-specific and lets mates identify each other. If a male's wing pigmentation continues to evolve in response to climate change and if a female's wings changes due to another factor, the researchers suspect eventually they may not be able to identify each other and mate, the team explains in a statement. Currently, it is still unknown why females respond less to climate change, but the team suspects that both sexes will not adapt to climate change the same way.
"Even though our research suggests these changes in pigmentation seem likely to happen as the world warms, the consequences are something we still really don't know all that much about yet," Moore said in a statement.
For future studies, the research team plans on learning more about the differences between male and female wings and look into what may be driving the variations genetically.