Tens of millions of insects traveled 100km of open sea to reach Cyprus on their way to mainland Europe, according to a study published in the journal Ecography.
A team of researchers from the University of Exeter, UK, analysed the migration of insects across Cyprus and Europe. They also examined satellite imagery to assess the amount of winter vegetation growth and identified the potential origins for the insects in Syria, Iraq, and Saudi Arabia.
“I had never seen anything like it. The sky was dark with insects, and we were being pelted by migratory flies, to the extent that we had to shelter behind the car door,” said lead researcher Will Hawkes, a Ph.D. student from the Centre of Ecology and Conservation at the University of Exeter’s Penryn Campus in Cornwall. In just one month, the team observed almost 40 million insects arrive at the tip of the Karpaz peninsula in Cyprus.
“We had a hunch that this would be an important site for insect migration, but we were blown away by the intensity of the movement, which reached a rate of nearly 6,000 insects per metre per minute,” added Dr. Karl Wotton, also from the University of Exeter.
As the researchers note, it wasn’t just the number of insects that was impressive, but also the diversity. The team found a large number of Vagrant Emperor dragonflies and Painted Lady butterflies, but there were also many types of flies and other species of insects.
Knowing what insects are migrating allows researchers to understand what effects their movements have on the planet. For example, the arrival of hoverflies carrying orchid pollen from Asia is evidence of “cross-continental pollination.” This long distance transfer of genes transported by migrant insects gives plants access to a diverse gene pool and potentially ways to cope with changing environment.
“These migratory insects are really important at a local ecological level too,” said Hawkes. “We saw ants eating Painted Lady butterflies, and even migratory locusts and butterflies being eaten by turtles.”
The researchers highlighted that human activity and climate change could affect the migration routes and ranges of many of these insect species. As such, we must take a more global, holistic view of conservation.
“Migratory insects are vulnerable to habitat loss beyond the boundaries of one country,” concluded Hawkes. “If we all take an interest in these remarkable little creatures, we can protect them and reap the rewards for doing so.”
A video clip of the migrating insects is available here: https://www.youtube.com/watch?v=aShEKcchRyI
Hawkes W, Walliker E, Gao B, Forster O, Lacey K, Doyle T et al. (2022) Huge spring migrations of insects from the Middle East to Europe: quantifying the migratory assemblage and ecosystem services. Ecography, https://doi.org/10.1111/ecog.06288