Hard-to-find insect, first recorded in 1933, is incapable of flight, looks like a spider and is thought to live only on one rock

This article is more than 9 years old

This article is more than 9 years old

Scientists in Kenya have located one of the world's rarest and oddest-looking flies after a long hunt for the insect, which has been described as the "terrible hairy fly".

The yellow-haired fly was first recorded in 1933, and again in 1948. Since then, at least half a dozen expeditions have visited a site between the towns of Thika and Garissa to try to find it.

Incapable of flight and partial to breeding in bat faeces, the fly is thought to live only in the bat-filled cleft of a single, isolated rock in the Ukazi Hills.

Mormotomyia hirsuta measures about 1cm long and, with hairy legs, looks like a spider, scientists said. It has non-functional wings that resemble miniature belt-straps, and tiny eyes.

Dr Robert Copeland, of the Nairobi-based International Centre of Insect Physiology and Ecology, said the fly's physical appearance had left scientists bamboozled about where exactly it belonged in the order of diptera, or "true flies".

"We have collected fresh specimens for molecular analysis to see where exactly the terrible hairy fly fits into the evolutionary process," Copeland said.

"The fly has no obvious adaptations for clinging on to other animals for transfer from one place to another. With its long legs, it could perhaps wrap itself around a bat and get a ride ... but it's never been found elsewhere."

Mormotomyia hirsuta is the only member of its biological family, and some experts believe it will eventually prove to be the only family of fly completely restricted to Africa.