The white-tailed phorid, Megaselia albicaudata

It is amazing to me that some phorid flies are found in multiple environments around the world. Less surprising are the scavengers that live mostly in human-built structures or that need scraps of our civilization to thrive. Usually, these scavengers are well-known to us, through their large numbers and occasional nuisance status. But what about the”white-tailed phorid” (I just made that name up, based on the Latin name!), an obscure but seemingly ubiquitous fly?albicaudlatsmall

There is no question that this 1.5 mm long fly is well-named: the male genitalia are a shocking white in comparison to the rest of the rather dingy brown body. It was described in 1910 from England, and is well-known from other parts of the world such as Finland, Israel, and China. It is also found in the two big fly inventories that I am part of: the Los Angeles County Natural History Museum’s urban biodiversity project called “BioSCAN” and the Costa Rican “ZADBI” project in a tropical cloud forest.

How can a species live in such disparate climates and habitats? Nobody knows, just as nobody knows what the larvae of this fly eat. I have looked at specimens from both North America and Costa Rica, and I am sure they are morphologically the same species, not two species masquerading as one doing different things in different places. It is one of thousands of Megaselia worldwide that we know nothing about, but discovering phorid lifestyles is part of our* phorid research effort. Obviously, we have a long way to go when such a widespread species remains a mystery.

*Note, when I say “our”, I mean the few people worldwide actively pursuing phorid research, including our group here at LACM, consisting of Emily Hartop, Lisa Gonzalez, and me.

Windows

No, not the operating system. I’m talking about physical windows in a building. If some doors, other windows, or even the whole side of the building are open, windows can be fantastic places to collect flies. Like most dipterists, I go right to the windows of any building I am in, to see what is there. Sometimes, people look at me as if I am crazy, but I forgive them because they just don’t realize how cool flies are yet (top to bottom, a ropalomerid, stratiomyid, and tababid).

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OLYMPUS DIGITAL CAMERA

OLYMPUS DIGITAL CAMERA

Wendy Porras and I just got back from La Selva Biological Station in Costa Rica, where half of the dining room is wide open, while the other half has screened windows throughout. We found a lot of extremely photogenic flies, some of which I show here. We put them in a more pleasing background than screening, wrangled them to sit still, and got the shots we wanted. A little honey on the leaves helped, as some flies were apparently hungry after several hours of banging their heads against metal cables.

Diptera Blitz wrap-up

EOL micropezidOf course, our event was a tremendous success. Some highlights:

– bat-netting by Carl Dick got us streblid records, bird-netting by Kimball Garrett got some hippoboscids.

– Carlos de la Rosa (the Director of the La Selva Biological Station) joined the team, working on chironomid midge pupal exuviae

– Michael Turelli, professor of genetics at UC Davis and (at least on this trip) amateur drosophilid collector gave a stunning talk about using the intracellular bacterium Wohlbachia to eliminate dengue

– the final event, a barbeque, featured a short film about the week by LACM videographer Edgar Chamorro.

Some photos follow, including a group photo of nearly all participants. These photos help portray not only the enjoyment, but also the dedication of the team to document as many Zurqui flies as possible. The results of their efforts will appear soon on this website.

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Yes, nearly all these people came to Costa Rica to study flies! (click photo for larger view)

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LACM ornithologist Kimball Garrett releasing a bird after checking it for hippoboscids (bird louse flies)

Manuel Art Brian
Manuel Zumbado, Brian Brown, Art Borkent: three dipterological amigos

Diptera blitz continues

Uber-collector Wayne Mathis

Uber-collector Wayne Mathis

The 30 participants in the Zurqui all Diptera biodiversity inventory in Costa Rica have been pushing back our veil of ignorance about the fly fauna of tropical cloud forests. So far, we have spent two full days at the site (Zurqui de Moravia, 20 minutes north of San Jose), and one full day at our partner institution INBio. New species and even new genera of flies are being found everywhere we look. Some examples:

Collaborators Dr. Greg Curler and Sergio Ibanez have found a strange new type of psychodid (moth fly) that holds its wings unlike any other they have ever seen. Most moth flies hold their wings either flat over the body, or roof like over the body; this one inverts its wings over the body so that they make a trough. Significance? Who knows, but it is amazing that such a fundamentally different body form has been found. Last night, Curler hoisted some light traps up into the canopy of the forest to see what other strange things he could discover. Stay tuned for what he found.

Collaborator Dr. Wayne Mathis has been collecting for several days and has pushed our family list to 69 with this collection of diastatids (sorry, no common name), therevids, and anthomyzids, as well as boosting the list of shore flies (Ephydridae) to 26 species.

Netting bats at night has been particularly productive for inventorying bat flies. Dr. Carl Dick has added several genera and species to our list that would never have been included if we had only relied on Malaise traps and other standard insect collecting methods.

In a small raid of army ants, Anna Holden I collected some bizarre short winged phorid flies running around with the ants. These flies, genus Acontistoptera, have fully winged males that transport them in-flight among army ant colonies. We know this because the flightless females turn up in our Malaise trap samples along with their more mobile mates.

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A tiny Acontistoptera female

Yesterday, we spent the day in the lab at our partner institution INBio, where our collaborators could interact with our Costa Rican staff and examine some of the ZADBI material in the collection. Collaborator Dr. Jeff Skevington looked at our 34 specimens of pipunculids (big headed flies) and pronounced almost every one of them a different species! Little duplication means that there are many more new things still to find.

 

This is just a taste of what has transpired over the last three days; I’ll get more reports from our scientists today. Lots of ideas have been exchanged, plans made for the future, and scientific papers outlined for publication. Two days still to go!

Giant flies with giant names

Kirks pantophthalmid

A Brazilian pantophthalmid. Yes, it is real.

Some of the largest flies in the world belong to a family called (believe it or not) Pantophthalmidae. The tongue twisting nature of this name aside, the English name “giant wood-boring flies” seems less impressive. They are found only in the Neotropical Region (South and Central America), where they are uncommonly collected, usually at light or on freshly cut wood. Although frighteningly large, these flies are utterly harmless. Their larvae, however, bore into dying or dead trees eventually growing to a large enough size to produce the iconic adults.

I have seen exactly two living adults of these flies, but recently in Costa Rica, we came across evidence of many more. We were staying at a resort oriented towards birders called “Hacienda Baru” that is situated close to sea level on the Pacific coast near Playa Dominical. It was hot and humid there, and the biting midges were fierce, but we made it through a few days before fleeing to the highlands.

Along the trails were logs cut from tree falls, and in some of them were living and freshly abandoned pupae of pantophthalmids. In the log photographed here, I counted 65 exit holes alone, and some other trees in the vicinity had hundreds of holes drilled by the larvae of these flies.

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empty pantophthalmid pupa

For those interested in encountering large numbers of giant wood-boring flies, Hacienda Baru should be the first place on your list!

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log full of pantophthalmid borings

(I thank Kirk Fitzhugh for the first image).

Getting lucky

Collecting flies while they are mating is a surefire way to establish conspecific identity. Many female phorids are extremely different in appearance than the males (search this site for lots of examples), and linking the two together can be almost impossible, based on morphology.
< Borgmeieriphora in copula

Borgmeieriphora in copula oblique

In this case, we have a pair of Borgmeieriphora collected in a Malaise trap by Wendy Porras in Costa Rica. The females are wingless, reduced creatures, which however have a sharpened, parasitoid type ovipositor. They lived in army ant colonies, but are rarely collected. The only large series of specimens known is a group that I caught over such ants at La Selva Biological Station many years ago. The males were flying over the ants, carrying the females, as many phorids do. Since then, males have shown up frequently in trap samples, but until now females almost never. This new capture was surely a huge stroke of luck, because most mating pairs separate before they die in the alcohol.

Something “new ” for Central America

When in Brazil a few years ago, my team of Giar-Ann Kung, Wendy Porras, and I found the spiny, brachypterous (short-winged) females of phorid genus Pheidolomyia. These flies, which live in the nests of the ant genus Pheidole, were only known from Brazil. Once back home in Costa Rica, however, Wendy quickly found them there, too. This demonstrates two important principles of dipterology: 1) Wendy is a great collector, and 2) our knowledge of the distribution of tropical flies is extremely fragmentary.

A female Pheidolomyia from Costa Rica - photo by Inna Strazhnik

A female Pheidolomyia from Costa Rica – photo by Inna Strazhnik

After I remarked on yet another interesting “South American” phorid fly showing up at La Selva Biological Station during the ALAS (Arthropods of La Selva) project, the ant ecologist Jack Longino agreed with me, only partly joking that “if you collect long enough at La Selva, you get the entire Neotropical fauna!” Now, that’s a hypothesis that would be fun to test.

Collecting weird lesser dung flies

I suppose I could have come up with a better title, but with all due respect to my friend and mentor Dr. Steve Marshall, the family Sphaeroceridae does not often lend itself to superlatives. You wouldn’t know this from reading his recent book, Flies: the natural history and diversity of Diptera, however, in which Steve gushes appreciatively about the hordes of dingy, drab brown flies that swarm over cow pies. He reserves special appreciation for the subfamily Homalomitrinae, a group he co-described with his colleague Jindrich Rohacek. These flies, unlike their relatively dull relatives, are bizarre looking creatures, with reduced wing venation, flattened heads, and thickened leg segments. The original specimen was a female collected with army ants in Brazil in 1930; others were found to be attracted to lights. The six known species are organized into three genera: 4 species in Homalomitra, 1 species in Sphaeromitra, and one in Podiomitra. There are fewer than 20 specimens known.

podiomitra-2

Look at the strange head, unusual “feet”, and incredibly reduced wing venation on this fly. Amazingly, we have collected at least three more already in our All Diptera Biodiversity Survey in Costa Rica, all from light traps. It will be interesting to see what other strange creatures are uncovered by our intensive survey of this tropical cloud forest. (photo by Inna Strazhnik).

Phorid parasitoids of endangered ants also endangered

When ant-decapitating flies have endangered hosts, they become endangered, too. Today in the journal Zootaxa, I describe three new species of phorids found by my co-authors Marcos A. L. Braganca, Diego S. Gomes, Jarbas M. Queiros, & Marcos C. Teixeiras. The three flies attack Atta robusta, a species of ant found only in restinga (sandbank) vegetation in a small area in Brazil. Two of the flies are Eibesfeldtphora species, while the other is a Myrmosicarius; all are parasitoids developing in the ant’s head. We don’t have photos, but I am taking the opportunity to show a couple of fabulous photos of another Eibesfeldtphora attacking leaf cutter ants in Costa Rica by Wendy Porras.

Eibesfeldtphora curvinervis about to attack a leaf cutter ant. Photo by Wendy Porras.

The fly laying an egg into the ant’s head through the occipital foramen (neck). Fabulous photo by Wendy Porras.

Terrifying photos. If these flies were the size of crows we’d never leave our houses!

Massive tropical fly inventory funded by the United States National Science Foundation

A tachinid fly photographed by Wendy Porras at Zurqui

I am excited to announce that NSF has funded Dr. Art Borkent and I to conduct an ambitious project to discover and enumerate all of the flies at a tropical site in Costa Rica. The site, called Zurqui de Moravia, or Zurqui for short, is about one half hour north of San Jose in the cloud forest just outside Braulio Carrillo National Park. We have been collecting there for the past 15 years, and have found one of the most diverse and interesting faunas in Costa Rica. Now we are extending our studies to ALL of the Diptera found there!

This project is a collaboration of more than 40 experts worldwide, as well as Costa Rica’s Instituto Nacional de Biodiversidad (INBio). Together, we will collect extensively and identify all groups, even the “impossible” ones like ceratopogonids, cecidomyiids, and phorids. We expect to find a number of species that will surprise even us!

This will be the first time that such an intense effort will be made for any mega-diverse group of insects in the tropics. We were inspired by Terry Erwin’s fogging samples in Peru (and elsewhere), but wanted to go a different route in understanding tropical biodiversity. The “All Taxon Biodiversity Inventory” (ATBI) model appealed to us, but we knew we had to restrict our collecting to prevent the project from getting out of hand. We therefore decided to collect in just two small ravines in an area 100 m x 200 m in size.

We are calling the project the “Zurqui All Diptera Biodiversity Inventory”, or ZADBI. Collecting will start in September; meanwhile we are getting organized for the massive job of collecting, preparing, and identifying the tens (or hundreds) of thousands of specimens we will collect. Of course, we will be broadcasting our discoveries and experiences both here on flyobsession and on the project’s website (TBD). Get ready for some more cool flies!