Red-bodied swallowtail butterflies look so delicate and beautiful that their discoverers named them after flower colors, such as crimson rose. But these eye-catching insects are more sinister than one might imagine.
If an unfortunate predator — even a human — decides to eat one, gagging and severe vomiting may follow. The aftermath is so miserable that victims rarely prey on the butterflies again.
The common Mormon swallowtail butterfly (Papilio polytes), conversely, tastes delicious to birds and other predators. That poses survival challenges for the insects, so females of the species have evolved the ability to look just like toxic red-bodied swallowtails.
Female common Mormons sport different colors, patches, and patterns, though, and only some mimic red-bodied swallowtails. This multi-form phenomenon reminded early entomologists of Mormons who historically practiced polygamy, whereby men may have several wives.
New research on common Mormons and other butterflies published in the journal Nature Communications finds that some populations of these insects have maintained multiple female forms — including mimics — for millions of years.
Understanding the genetic processes that led to these imposters could facilitate research on what are known as “sex-limited” traits and diseases in humans. This means that the conditions tend to affect one sex more than the other.
Lead author Wei Zhang of the University of Chicago’s department of ecology and evolution said the research helps to address classic evolutionary questions and better understand sex-limited traits and diseases in other organisms.
“As far as we know, sex-limited traits and diseases widely exist in many sexually reproducing species as well as in humans, such as baldness and red-green color blindness,” she said.