Heliconius butterflies can live up to 348 days, nearly 25 times longer than some related tropical butterflies, according to a study published Tuesday in Nature Communications.
The study found that the long-lived insects combine a pollen-based diet with evolved mechanisms that appear to delay physical ageing. Lead author Dr Jessica Foley studied lifespan and ageing patterns across the Heliconius genus.
Foley is a postdoctoral scholar at Tufts University’s Jean Mayer USDA Human Nutrition Research Centre on Ageing in Boston. Her team compared 28 Heliconius species using butterfly house data, mark-release-recapture studies and controlled experiments.
The researchers found that Dione juno lived 14 days after adulthood, while Heliconius hewitsoni lived 348 days. Other Heliconius species lived between 106 and 277 days.
Most adult butterflies rely on nectar, which mainly provides carbohydrates. Many Heliconius species also feed on pollen, which contains amino acids and lipids that support reproduction, energy storage and immunity.
The team withheld pollen from some butterflies to test whether diet alone accounted for their longer lifespans. Foley said the insects still lived longer than their non-pollen-feeding relatives, suggesting that they have evolved longevity mechanisms.
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Researchers also tested age-related decline with a grip-strength device called “The Pullinator.” Heliconius hecale, which can live up to 277 days, showed little or no decline in muscle function.
Dr Jaret C. Daniels of the Florida Museum of Natural History, who was not involved in the study, said insect groups can serve as useful models for studying longevity
