Tag: fly species

Tiny fly from Los Angeles has a taste for crushed invasive snails

Living individual of Draparnaud’s glass snail
Photo by Kat Halsey

As part of their project BioSCAN – devoted to the exploration of the unknown insect diversity in and around the city of Los Angeles – the scientists at the Natural History Museum of Los Angeles County (USA) have already discovered numerous insects that are new to science, but they are still only guessing about the lifestyles of these species.

“Imagine trying to find a given 2 mm long fly in the environment and tracking its behavior: it is the smallest imaginable needle in the largest haystack. So when researchers discover new life histories, it is something worth celebrating,”

explains Dr. Brian Brown, lead author of a recent paper, published in the scholarly open-access Biodiversity Data Journal.

However, Brown and Maria Wong, former BioSCAN technician, while doing field work at the L.A. County Arboretum, were quick to reveal a curious peculiarity about one particular species discovered as part of the project a few years ago. They successfully lured female phorid flies by means of crushing tiny, invasive snails and using them as bait. In comparison, the majority of phorid flies, whose lifestyles have been observed, are parasitoids of social insects like ants.

Within mere seconds after the team crushed tiny invasive snails (Oxychilus draparnaudi), females representing the fly species Megaselia steptoeae arrived at the scene and busied themselves feeding. Brown and Wong then collected some and brought them home alive along with some dead snails. One of the flies even laid eggs. After hatching, the larvae were observed feeding upon the rotting snails and soon they developed to the pupal stage. However, none was reared to adulthood.

Female phorid fly feeding on a crushed Draparnaud’s glass snail
Photo by Kat Halsey

Interestingly, the host species – used by the fly to both feed on and lay eggs inside – commonly known as Draparnaud’s glass snail, is a European species that has been introduced into many parts of the world. Meanwhile, the studied fly is native to L.A. So far, it is unknown when and how the mollusc appeared on the menu of the insect.

To make things even more curious, species of other snail genera failed to attract the flies, which hints at a peculiar interaction worth of further study, point out the scientists behind the study, Brown and Jann Vendetti, curator of the NHM Malacology collection. They also hope to lure in other species of flies by crushing other species of snails.

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In recent years, the BioSCAN project led to other curious discoveries from L.A., also published in Biodiversity Data Journal. In 2016, a whole batch of twelve previously unknown scuttle fly species was described from the heart of the city. A year later, another mysterious phorid fly was caught ovipositing in mushroom caps after Bed & Breakfast owners called in entomologists to report on what they had been observing in their yard.

Original source:

Brown BV, Vendetti JE (2020) Megaselia steptoeae (Diptera: Phoridae): specialists on smashed snails. Biodiversity Data Journal 8: e50943. https://doi.org/10.3897/BDJ.8.e50943

New ‘big-armed fly’ species named after former California governor Arnold Schwarzenegger

New species can be named for all types of attributes, but Natural History Museum of Los Angeles County entomologist Brian Brown knew exactly what name to give a bizarre new fly species he discovered in the Brazilian Amazon.

“As soon as I saw those bulging legs, I knew I had to name this one after Arnold,” says Brown. “Not only is he a major cultural icon and an important person in the political realm, his autobiography gave me some hope that I could improve my body as a skinny teenager.” For these reasons, Brown says, the former governor deserves to have the new fly named in his honor.

His research article is published in the open access Biodiversity Data Journal.

The fly is impressive in other ways, Brown explains. “It is known only from one female specimen that we almost overlooked because it is so incredibly small.”

In fact, it is the world’s smallest known fly, according to Brown, who should know, since he had previously described what was formerly the world’s smallest fly, at 0.400 mm in body length. The new fly, named Megapropodiphora arnoldi, is just a fraction smaller, coming in at 0.395 mm.

MegapropodiphoraHowever, 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.

Even though the fly has not been observed in the wild, Brown concludes that it is clearly a parasitoid, probably of ants or termites, based on its pointed, sharp ovipositor. 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 parasitize their victims more effectively.

Brown has had considerable success finding new species of tiny flies, which he says are “the continuing frontier for insect discovery.”

Some of the more obvious, larger insects might have already been described, but by looking at smaller specimens, especially from remote, tropical sites, the entomologist finds that almost everything is new.

Even in his home city of Los Angeles, Brown and collaborators found that almost half of the phorid flies were previously unknown.

For example, it was last year that they finally figured why a secretive fly had been observed around mushrooms with no clear explanation for nearly 30 years. The revelation occurred when L.A. Bed & Breakfast owners Patsy Carter and Lisa Carter-Davis decided to alert entomologists about a phenomenon happening in their yard.

Back in 2016, Brian and his team described at once a total of twelve scuttle fly species new to science after ‘field’ trips in the backyards of houses around the city of angels.

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Original source:

Citation: Brown B (2018) A second contender for “world’s smallest fly” (Diptera: Phoridae). Biodiversity Data Journal 6: e22396. https://doi.org/10.3897/BDJ.6.e22396