Scientist have discovered a fly that... can't fly.
In December 2021, the John Midgley and Burgert Muller from the Diversity of Pollinating Diptera in South African Biodiversity Hotspots project went to Lesotho, the only country in the world that has its entire territory located at an altitude of 1,000 metres and higher to see what they could find.
At the Afriski mountain resort, they found 51 male specimens of Atherimorpha latipennis(a species discovered in 1956 but whose female had never been described) and a for the first time a female belonging to the same species which couldn't get off the ground.
“It’s not unheard of for only the female of a species to be flightless,” says Midgley. “But there were no examples in this fly’s family, let alone its genus.”
Martin Hauser, a senior dipterologist at the California Department of Food and Agriculture, who was not involved in the research, toldthe Guardian: “Active flight has only originated four times in the last three billion years, so it’s always interesting when a species loses the ability to fly. It isn’t super surprising to find flightless species. But it is remarkable when the first case of flightlessness is reported in a family.”
Scientists could only make educated guesses about why the female had lost the ability to fly.
Despite it being much faster than walking, allowing flies to escape predators. “flight is also costly,” said Midgley. “You have to grow wings, and it uses a lot more energy than walking.”
“For the males it is worth flying around and being able to search a larger area for females,” said Hauser. “Even if, while flying, they are exposed to birds and other predators, and risk being blown off the mountain and ending up in a hot valley with no females.”
Meanwhile, there are other species that can't fly like ostriches, kiwi and emus. It is thought they evolved to lose flight after the dinosaurs became extinct because there were no predators big enough to hunt them.