Professor Tom Oliver, an ecologist at the University of Reading and co-author of the study, said: "We know that the number of Painted Lady butterflies in Europe varies wildly, sometimes with 100 times more from one year to the next. However, the conditions that caused this were unknown, and the suggestion the butterflies could cross the Sahara desert and oceans to reach Europe was not proven. "This research shows this unlikely journey is possible, and that certain climate conditions leading up to migration season have a big influence on the numbers that make it. The Painted Lady migrates during the spring, following a winter breeding season. Painted Lady caterpillars feed on the leaves of plants that thrive in wetter winter conditions in the Savannah and Sahel regions of sub-Saharan Africa, causing population numbers to explode.

Source: The North Africa Journal June 22, 2021 13:30 UTC