Butterflies Brave the Atlantic

Painted lady butterflies (Vanessa cardui) are already known for their global presence and migration patterns. But a new study reveals these intrepid insects migrate across oceans, covering incredible distances.

Published in Nature Communications, the research details how these butterflies travel a minimum of 2,610 miles (4,200 km) over the Atlantic, from West Africa to French Guiana. The study further suggests that, including the point of emergence, the journey could exceed 4,345 miles (7,000 km).

"The overall journey, which was energetically feasible only if assisted by winds, is among the longest documented for individual insects, and potentially the first verified transatlantic crossing."

The study also highlights the underappreciated phenomenon of insect long-distance dispersal (LDD), due to challenges in tracking small, short-lived creatures over vast distances.

Tracing the Journey

In October 2013, three exhausted Painted Ladies were found on a beach in French Guiana, their wings damaged from a strenuous ocean crossing. Given the absence of stable populations in South America, researchers used wind trajectory data to determine the butterflies' origin: West Africa.

Global Travellers

According to the University of Colorado Boulder's Museum of Natural History, these butterflies are found on every continent except Australia and Antarctica. Their migration patterns are influenced by factors like El Niño, triggering movements in various directions.

A Butterfly's Delight

To attract these beautiful butterflies to your garden, plants from the Asteraceae family, like thistles, are a favorite. Mallows from the Malvaceae family, legume plants, alfalfa, and clover are also sure to lure these vibrant creatures. For their caterpillars, herbs and insecticides are a no-go, as they love to munch on the very same plants that attract their parents.

Sources

• Nature Communications: Transatlantic wind-assisted migration of painted lady butterflies
• Wisconsin Horticulture: Painted Lady Butterfly, Vanessa cardui
• University of Colorado Boulder's Museum of Natural History: Painted Lady Butterfly
• Gardenia: Painted Lady Butterfly
• Insect Lore: Best Host Plants for Painted Lady Butterflies