Scientists find first evidence that butterflies crossed the Atlantic Ocean

Sub: Environment

Sec: Species in news

Context:

Scientists discovered that butterflies made a 2,600-mile journey across the Atlantic Ocean.

Details:

Gerard Talavera spotted painted lady butterflies in French Guiana in 2013, which was unusual since they are not typically found in South America.
After a decade of investigation, it was concluded that these butterflies undertook the first recorded transoceanic flight by an insect.

Scientific Investigation and Evidence:

Researchers sequenced the butterflies’ genomes and found they were closely related to populations in Europe and Africa.
Pollen DNA on the butterflies indicated origins from tropical Africa.
Isotopes of hydrogen and strontium on their wings were unique to Western Europe.
This evidence suggested the butterflies originated in Africa or Europe, not North America.

Details of the Migration Journey:

The painted lady butterflies likely flew from West Africa to South America, a distance of at least 4,200 km.
The journey might have been even longer, potentially starting in Europe, totalling up to 7,000 km.
Painted lady butterflies are known for long migrations, such as the 9,000-mile trip between Europe and Africa.

Mechanism of Long-Distance Flight:

To reach French Guiana, butterflies would need to fly up to eight days without rest.
Scientists analyzed wind currents from the Sahara, which could help butterflies glide and conserve energy.
Alternating between minimal effort gliding and active flight was crucial for the journey.

Implications and Perspectives:

This discovery reveals insects’ ability to traverse vast distances, potentially impacting ecosystems more than previously thought.
It suggests that long-distance insect migrations may be more common and significant than currently understood.

Painted Lady (Vanessa cardui):

Vanessa cardui is the most widespread of all butterfly species. It is commonly called the painted lady, or formerly in North America the cosmopolitan.
Found on every continent except Antarctica and South America.
Adult butterflies feed on flower nectar and aphid honeydew.