Painted lady butterflies don’t migrate like birds — ask their genes Premium

For many years, scientists had had difficulties studying migration in insects because of their size and experts’ inability to track their movement thanks to technological limitations. But a boom in genomics and the development of tracking technologies in miniature has allowed researchers to delve into insect migration with astounding precision.

Some plants, like snapdragons, can produce a wide range of colourful flowers. The difference between two flowers of different colours can be elicited by comparing their genomes and spotting the differences there, according to Daria Shipilina, a researcher at the Institute of Science and Technology Austria.

As an evolutionary biologist, Shipilina is fascinated by how genes in an organism’s genome contribute to its observable traits, or phenotypes. A phenotype is a physical, biological, or behavioural characteristic shaped by genetics as well as environmental factors. Examples include skin and hair colour in humans, vocal behaviour among birds, and the migratory patterns of some animals.

“Migration is a very complex phenotype,” according to Shipilina. “With colors, it’s quite easy — we see it with our eyes.” But migration is a complex adaptation that involves traits such as migratory timing, orientation, distance covered, and wing shape and size.

For many years, scientists had had difficulties studying migration in insects because of their size and experts’ inability to track their movement thanks to technological limitations. But a boom in genomics and the development of tracking technologies in miniature has allowed researchers like Shipilina to delve into insect migration with astounding precision.

Taking advantage of the new tools at her disposal, Shipilina has been studying if there are both short-distance and long-distance migrants among butterflies as there are among birds, by phenotyping them.

“For birds, we know a lot — we understand their migration routes and how genes control their migratory behavior in some species,” Shipilina said. “We know practically nothing about insects and specifically genomics of insect migration comparatively.”

In a study published recently in the journal PNAS Nexus, her team of researchers from institutes in Austria, Benin, Canada, Senegal, Spain, and Sweden reported that short- and long-distance migrants among painted lady butterflies (Vanessa cardui) don’t have significant genetic differences between them. Instead, the distances across which each member migrates appears to be influenced by environmental conditions.