Meet a fly named after Schwarzenegger

Fiji is home to the endangered Ba humbugi snail, and in Borneo is found the type of mushroom Spongiforma squarepantsii.

With tens of thousands of new species discovered each year, it can be a bit tricky coming up with names for them. There are rules to be followed: they must be unique, and conform to the International Code of Zoological Nomenclature, using the letters of the Latin alphabet, and they must be published.

But when US entomologist Brian Brown made his latest discovery of a bizarre new fly species in the Brazilian Amazon, he knew just what name to give it.

He named the fly Megapropodiphora arnoldi, in honour of the bodybuilder-turned-actor and former governor of the US state of California, Arnold Schwarzenegger.

“As soon as I saw those bulging legs, I knew I had to name this one after Arnold,” Brown says.

His choice of name, while well-meaning, might seem slightly off the mark. “It is known only from one female specimen that we almost overlooked because it is so incredibly small,” Brown says.

In fact, it is the world’s smallest known fly, according to Brown, who should know, because he had previously described what was formerly the smallest fly, Thailand’s Euryplatea nanaknihali, at 0.4 millimetres in body length. The new fly is just a fraction smaller, coming in at 0.395mm.

And unlike the enlarged forelegs that prompted the naming, the mid and hind legs appear to be highly reduced, and the wings reduced to tiny stubs.

Of Schwarzenegger, Brown says he is “a major cultural icon and an important person in the political realm”, and that reading the actor’s autobiography “gave me some hope that I could improve my body as a skinny teenager”.

Even though the fly has not been observed in the wild, Brown concludes that it is a parasitoid, whose larvae live as parasites which eventually kill their hosts – probably of ants or termites, based on its sharp egg depositor. He further speculates that these flies probably grab onto the hosts and “hold on for dear life” until they reach a nest or colony, where they can inject their eggs into their victims more effectively.

Brown, who is on the staff at the Natural History Museum of Los Angeles County, in California, and published his new research article in Biodiversity Data Journal, says new species of tiny flies are “the continuing frontier for insect discovery”.

Working in Los Angeles, Brown and collaborators have found that almost half the flies they observed were previously unknown.

In 2017, for example, they finally figured out why a secretive fly had been observed around mushrooms, with no clear explanation, for nearly 30 years.

Following up a call from the owners of a Los Angeles bed-and-breakfast, Brown’s team found that mushrooms growing in the backyard of the B&B were hosting the mysterious flies. Females were depositing their eggs in the mushroom caps, with the larvae subsequently developing and feeding on the lower surface of the fungi, deep within the gills. Later, the larvae would exit the mushroom to pupate into the soil underneath before emerging as adults.

As reported in Biodiversity Data Journal, the team collected specimens of the previously unknown males, which allowed them to successfully identify the mysterious species as Megaselia marquezi.