Genetic Analysis
Researchers found no significant genetic differences between short-distance and long-distance migrating painted lady butterflies.
This suggests that unlike birds, where genetic traits often influence migration routes, butterflies rely more on environmental factors.
The study challenges the traditional focus of migration genetics on birds, highlighting the need to understand insect migration differently.
Migration Pattern
Painted lady butterflies are known for their remarkable long-distance migration, covering up to 15,000 km in one cycle, one of the longest insect migrations globally.
Their migration is multi-generational, involving 8–10 generations, with each butterfly living only 2–4 weeks, making it a "family business" where offspring continue the journey.
They migrate seasonally between Europe and North Africa, with adults flying north in spring and their offspring returning south in late summer and autumn.
Isotopic Tracking
Researchers analyzed the stable isotopes of hydrogen and strontium in the butterflies’ wings, which absorb these elements from food and water during their larval stage.
Since butterfly wings are metabolically inactive after formation, they preserve the isotopic signature of the environment where the butterfly was born, acting like a natural GPS.
Using isotopic maps (isoscapes) from Europe and North Africa, scientists determined the butterflies’ places of origin and estimated the distances they migrated.
Study Findings
The study revealed that butterflies form a single interbreeding population, regardless of the distance they migrate.
Factors like wing size, shape, and wear do not significantly influence how far a butterfly migrates, contrary to common assumptions.
Some butterflies that traveled up to 4,000 km showed minimal wing wear, suggesting that wear is not a reliable indicator of migration distance.
Painted lady
The painted lady also called as the thistle butterfly, is native to Canada and cannot survive colder climates.
Scientific Name - Vanessa cardui.
The insect is a champion of long-distance travel, routinely crisscrossing the Sahara on a trek from Europe to sub-Saharan Africa, and covering up to 9,000 miles.
It has orange wings with black tips. The upper side of the forewings have a pattern of white spots and thick black lines.
This butterfly can be found almost anywhere, from the seashore and town gardens, to the tops of the highest mountains.
It is one of the world’s most widespread butterflies, but it isn’t found in Antarctica and South America.
It fed on Thistles, the primary food plant of this species.
This is one of the few species that can breed in intensive farmland since even these sites typically contain a patch of Thistles.
IUCN conservation status : Least Concern
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