Scientists from the University of Bristol studied a group of tropical butterflies and discovered they may slow down aging to live much longer.
The butterflies belong to the Heliconius tribe, which lives in the rainforests of Central and South America. These insects are among the longest‑lived butterflies ever recorded.
Most butterflies survive only a few weeks as adults. In the new study, some Heliconius species lived about three times longer than their close relatives. One species, Heliconius hewitsoni, lived up to 348 days, while a similar butterfly, Dione juno, survived just 14 days – a 25‑fold difference.
The researchers think Heliconius butterflies have a special way of extending life that could teach us how aging slows down in nature.
Evidence of Slower Aging
Working with the Smithsonian Tropical Research Institute in Panama, the team found that a species called Heliconius hecale showed almost no physical decline as it got older.
They tested grip strength to measure performance. Old H. hecale butterflies were just as strong as young ones. By contrast, a related short‑lived species, Dryas iulia, got weaker with age.
These results suggest Heliconius butterflies may avoid the usual wear and tear that comes with aging.
To reach these conclusions, the scientists combined data from butterfly houses, mark‑release‑recapture studies, and controlled lab experiments. They compared lifespan and aging across the Heliconiini tribe.
Overall, Heliconius butterflies showed longer average and maximum lifespans, lower death rates, and slower aging than relatives that do not eat pollen.
The Role of Pollen Feeding
One reason for the long life may be that adult Heliconius butterflies can eat pollen, which is rare among butterflies. Most species only drink nectar.
The researchers compared the pollen‑eating H. hecale with the non‑pollen eater Dryas iulia. The pollen‑eater kept its body weight and muscle strength longer and did not show age‑related decline.
Even when pollen was removed from the diet, H. hecale still lived much longer than its relative, indicating that both nutrition and genetic adaptations help its longevity.
A New Model for Longevity Research
Long‑lived animals can give scientists clues about healthy aging. The study suggests Heliconius butterflies could become a useful model for exploring how ecological changes, like adult pollen feeding, promote longer life.
"Heliconius butterflies live far longer than close relatives and seem to age more slowly," the researchers said. "This natural experiment lets us study the biology of aging and could point to ways to extend healthy life spans in other animals."