Diptera » Biodiversity in Focus Blog

I’m Dreaming of A #BlackFlyDay

Biology, Diptera, Fun Stuff 2 Responses »

Nov 272015

American Thanksgiving not only marks the beginning of left-over turkey sandwich season, but has also come to represent the official start of the Holiday Season™. Traditionally rung in with the rampant purchasing of sale-priced items, the beginning of Holiday Season™ is now celebrated instead with Black Fly Day. This year, in preparation for ugly sweater parties and more family gatherings than should ever occur in such short succession, I present to you 6 fun facts about black flies that will keep your friends and family utterly enchanted!

Simulium sp from Ecuador Black fly Simuliidae

Simulium (Psilopelmia) bicoloratum from Ecuador (Simuliidae) feasting on my blood.

The Mystery of the Unexplainable Life History

Biology, Cool Science, Diptera 1 Response »

Sep 292015

What makes a good mystery? Well, usually a death is involved, there’s an unexpected plot twist along the way, and undoubtedly a shadowy figure no one expects ends up playing a central role. Toss in a few scorpions, a handful of maggots, and a dead body and you’re well on your way to a New York Times bestseller! But perhaps I’m getting ahead of myself, s0 allow me to set the scene.

Mesobuthus martensii

The Chinese scorpion, Mesobuthus martensii, is a species of medical interest, not just because it has a stinger and can inflict injury on others, but because the chemicals of its sting are being explored for our use in medicine. Peptides produced in the stinger have been used as antimicrobial agents, have been shown to reduce convulsions in epileptic rats and cancerous tumours in human cell cultures. However, because of its newfound value to medicine (and a long-standing role in Chinese traditional medicine), wild populations of the Chinese scorpion are declining across their native range (from Mongolia to North Korea and Japan), and the species is now considered vulnerable by Chinese conservation biologists. Needless to say, this is one scorpion species whose natural history would be good to understand, and yet one we know very little about.

Working from a brief and poorly recorded observation of fly larvae hanging around a dead scorpion, a team of researchers lead by Cheng-Min Shi set out to understand the natural enemies and parasitoids of the Chinese scorpion and started by combing Niushou Mountain for scorpions, collecting a few hundred scorpions in the process. They then brought the live scorpions back to the lab and waited and watched to see what would happen. What they found however, raised many more questions: questions that extend far beyond the mountains of Northeastern China.

Of the 317 specimens they brought back to the lab, 73 died within the first nine days, the majority of which soon spawned dozens of wriggling, late-instar maggots. After rearing many of these maggots to adulthood, and sequencing the DNA of both adults and larvae, the researchers were able to put a name on the first recorded parasitoid for this important scorpion species: Sarcophaga (Liosarcophaga) dux, a species of flesh fly in the family Sarcophagidae. Parasitoid flesh flies aren’t that unusual; flesh flies have been recorded in a wide variety of hosts, from grasshoppers and millipedes to crabs, and even frogs. And flies parasitizing scorpions isn’t even that unique; there are tachinid flies that are known parasitoids of other scorpion species. But what is unusual is that we had already found the larvae of Sarcophaga dux before, and they didn’t come out of a scorpion.

It turns out that Sarcophaga dux is actually a relatively common species of flesh fly, known from across Asia and Europe, with a range stretching all the way from Japan to France. The species has even managed to spread throughout the South Pacific, reaching as far away as Australia and Hawaii. Until now we had thought it to have been closely associated with humans, following us around the world and feeding upon our waste, among other things: an adult fly was once captured on a dead body in Switzerland and studied for forensic purposes, while a few maggots were removed from the ear of a newborn baby in Thailand, which, it bears pointing out, is definitely not the same thing as a scorpion. So now we have a species that in some places is a parasitoid, in other places a saprophage (feeding on microbes and fecal matter), but also a sarcophage when the opportunity arises (feeding on dead stuff that it didn’t kill itself). Oh, and it can cause myiasis and survive by eating living tissue, like in that baby’s ear, or in cattle. It’s not uncommon to see a range of species in a genus exhibit each of these different life styles, or even for species to evolve from one life style to another as they shift from generalists to specialists (or vice versa). The Sarcophagidae in particular have evolved parasitic and parasitoidism many times independently, but an all-in-one package like this? That’s unheard of.

How can a species display a life history that ranges from the incredibly specialized role of scorpion parasitoid to a jack-of-all-trades at home in the big, bright world of garbage, dead bodies, and ear canals? By all accounts a parasitoid without its host should die, and a generalist omnivore should not be able to outsmart the immune system of a scorpion. Welcome to the mystery of the unexplainable life history.

Can you tell which specimen comes from where? Left, from Thailand (assumably collected with carrion bait)(Sukontason et al., 2014); Centre, from Thailand, aural myiasis in child (Chaiwong et al., 2014); Right, male reared from scorpion (Shi et al., 2015).

Can you tell which Sarcophaga dux specimen comes from where based on the male genitalia? Left, from Thailand (assumably collected with carrion bait)(Sukontason et al., 2014); Centre, from Thailand, aural myiasis in child (Chaiwong et al., 2014); Right, from China, reared from scorpion (Shi et al., 2015). Click to enlarge and take a closer look.

Clearly something is going on here, and it’s going to take some very careful sleuthing to figure out what Sarcophaga dux really is. By looking at the genitalia of male flies, the tool that cracks the case for most fly taxonomists, you’d be hard pressed to tell which specimens had been raised inside a scorpion and which came from free-ranging maggots. But when Shi and colleagues looked closer at the DNA, they found that the flies they reared from scorpions differed from the rest of the Sarcophaga dux specimens by a consistent 1.25%. And while a genetic difference of 1.25% may seem insignificant, it represents the first clue that Sarcophaga dux may be more than just a single species with a confoundingly diverse life history.

And that’s the best thing about studying natural history and taxonomy. Unlike a mystery novel that’s wrapped up with a nice, pretty bow by the final page, when we begin unravelling one taxonomic mystery, we invariably stumble upon a new wave of unknowns just waiting for our curiosity to be piqued.

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Main paper:

Shi, C.-M., Zhang, X.-S. & Zhang, D.-X. (2015) Parasitoidism of the Sarcophaga dux (Diptera: Sarcophagidae) on the Mesobuthus martensii (Scorpiones: Buthidae) and Its Implications. Annals of the Entomological Society of America. http://dx.doi.org/10.1093/aesa/sav090

Supplementary papers:

Chaiwong, T., Tem-Eiam, N., Limpavithayakul, M., Boongunha, N., Poolphol, W. & Sukontason, K.L. (2014) Aural myiasis caused by Parasarcophaga (Liosarcophaga) dux (Thomson) in Thailand. Tropical biomedicine 31, 496–8.

Sukontason, K.L., Sanit, S., Klong-Klaew, T., Tomberlin, J.K. & Sukontason, K. (2014) Sarcophaga (Liosarcophaga) dux (Diptera: Sarcophagidae): A flesh fly species of medical importance. Biological research 47, 14.

Home on the Range in the 21st Century

Biology, Cool Science, Diptera, Nature 1 Response »

Jun 242015

Oh give me a home where the buffalo roam,
Where the deer and the antelope play,
Where seldom is heard a discouraging word,
And the skies are not cloudy all day.

When it comes to evocative imagery of North American landscapes, perhaps no other song brings nature to life like Home on the Range. Sung round a campfire, your imagination can’t help but picture the Great American Plains teeming with life and big game under wide open skies as far as the eye can see. Yet, even as Dr. Brewster Higley was writing Home on the Range in 1876, the ecosystem that inspired him was already being drastically altered, and within a decade only a few hundred buffalo would roam where millions had previously.

And while buffalo, or more properly, bison, have largely been extirpated from their home on the range, they left behind an ecological footprint, if not hoofprints, that may influence the ways in which the deer and the antelope, but also the sheep, play.

When we think of animal engineers, we normally think of the beaver, reshaping waterways with dams and lodges carefully crafted with no regard for canoeists or property owners. But bison are known to wallow in their own environmental ingenuity as well, quite literally. Buffalo wallows are depressions in the plains that after decades of communal use by bison herds develop a layer of water-impermeable soil that helps trap water and mud near the surface, which in turn draws more and more wildlife to them during the hot, dry, summer months. These communal baths are even visible from space, and have stuck around for centuries even where bison no longer visit.

By rolling around and washing off all manner of biological material, from skin and hair to dust and plant matter, along with all manner of bodily fluids (bison aren’t adverse to peeing in the pool, so to speak), these wallows, when used, become highly enriched with organic matter. And where there are pools of organically-rich, wet, mud, there are undoubtedly a range of flies just waiting to make themselves at home.

Enter new research by Robert Pfannenstiel and Mark Ruder of the Arthropod-Borne Animal Diseases Research Unit of the USDA in Kansas. Pfannenstiel and Ruder wondered whether biting midge larvae (Ceratopogonidae) in the genus Culicoides were more likely to be found in wallows that haven’t been used for generations but which still collected water, or in wallows that rebounding bison have adopted and infused with fresh fertilizer.

When it comes to aquatic fly larvae associated with “Arthropod-Borne Animal Diseases”, Culicoides may not seem an obvious choice, with things like mosquitoes and black flies more often drawing our attention. But just as the megafauna of the Great Plains has changed since 1876, so too has its microfauna.

In the late 1940’s, a new disease began to emerge in the sheep and cattle of the Southwest, first in Texas, and then California. Termed “soremuzzle” by ranchers and shepherds, infected livestock, particularly sheep, would develop swelling and ulcers in and around their nose and mouth, become fevered, pull up lame, and in some extreme cases, the animal’s hooves would fall right off. Then, in 1952, immunologists finally put the pieces together and realized “soremuzzle” was actually Bluetongue Virus (BTV), a vector-borne disease only known from Africa and the Mediterranean at the time. Since then, Bluetongue Virus has spread from the American Southwest up throughout the plains and has begun creeping into the Midwest, as well as spreading to all the other sheep-inhabited continents, recently becoming a major concern for shepherds in the UK.

The wide spread of BTV was made possible in part by ranchers shipping infected sheep (which commonly don’t show signs of infection, and can remain infectious for weeks following initial exposure) around the globe, but also by the close relationships among the virus’ vectors, biting midges in the genus Culicoides. In the Mediterranean, the only vector had been Culicoides imicola, but eventually enough infected livestock spread into the neighbouring ranges of Culicoides obsoletus and C. pulicaris in Europe, who then helped spread the disease all across the continent.

Meanwhile, in North America, another pair of Culicoides species with wide ranges of their own found themselves home to BTV, Culicoides sonorensis, and Culicoides insignis, bringing us back to buffalo wallows and muddy waters.

Culicoides sonorensis – Photo copyright Adam Jewiss-Gaines, used with permission.

Pfannenstiel and Ruder scooped mud from buffalo wallows in and around the Konza Prairie Biological Station in Kansas (where, incidentally, the state song just so happens to be Home on the Range), some of which were currently being used by bison, and some of which had not been visited by bison for years, and reared the Culicoides larvae from each sample in the lab. They found that active bison wallows were home to Culicoides sonorensis (as well as several other closely related Culicoides species), with several dozen specimens reared from mud collected throughout the summer, while relict wallows were not.

All of this leads to an extremely complex conservation conundrum. By bringing back bison, and allowing them to resume wallowing in their wallows, it seems we’re increasing habitat for a fly species that carries a disease not present the last time bison roamed the range. Bison themselves are susceptible to BTV, but like cattle, don’t normally show the extreme symptoms or mortality that sheep do. However, the bison’s range is also home to nearly half of America’s sheep, with more than 2 million heads grazing the same areas as bison once roamed. More bison may equal more Culicoides, which in turn could equal more cases of BTV among livestock, a prospect that likely won’t sit well with ranchers and shepherds in the area.

What’s more, sheep aren’t even the most susceptible plains animals to BTV. While most infected sheep may show clinical signs of BTV infection, usually less than 30% of infected animals actually succumb to the disease. Meanwhile, the deer and the antelope (pronghorn) playing alongside the wallowing bison and grazing livestock experience an 80-90% mortality rate when infected with BTV, and will likely serve to spread the disease further, faster.

Of course, being a vector-borne disease, BTV can only spread as far as its vector is found, and unfortunately, we’ve been caught a little unprepared to answer just how far that may be. Culicoides are difficult to identify, and so we don’t know where these flies may or may not be found currently, and more importantly, where they may spread to in the future as climate change broadens acceptable habitat. Luckily, researchers like Adam Jewiss-Gaines, a PhD student at Brock University, are working to not only figure out where Culicoides‘ are found, but are also developing keys and resources that will allow others to track the great migration of these tiny flies.

Conservation biology is complicated, and fraught with trade-offs, especially when we try to conserve species in landscapes on which we place a high economic value and which we have changed immutably. So while we’ve brought bison from the brink of extinction back to Home on the Range-era levels, we now find ourselves presented with a new range of conservation challenges, and there may yet be dark clouds in our future skies.

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Pfannenstiel, R. S., and M. G. Ruder. 2015. Colonization of bison (Bison bison) wallows in a tallgrass prairie by Culicoides spp (Diptera: Ceratopogonidae). J. Vector Ecol. 40: 187–90.

Peekaboo, Swiftly

Biology, Cool Science, Diptera 2 Responses »

May 282015

Check out this video that Matthew Cobb of Why Evolution is True just found and posted. While it’s primarily showing a pair of swifts (Apus apus) being reunited after a 9 month hiatus in Africa, check out who crashes the party (most easily seen around the 1:10 mark).

That little scuttling thing playing peekaboo from the neck feathers of the male is actually an adult fly in the family Hippoboscidae, and most likely a male Crataerina pallida, the swift louse fly. These flies are ectoparasites of birds, where they bite and feed off the blood of both nestlings and adults.

Hippoboscids, like bat flies in the family Nycteribiidae (sometimes considered a subfamily of the Hippoboscidae) that Piotr Naskrecki has been showing off this week, give birth to live, late-stage maggots that the female has reared and nourished one at a time in her abdomen. The maggots are deposited into the swift’s nest, where they pupate and then scuttle onto their nestling host. According to Hutson (1981), fly populations peak in mid June when the swift nestlings are just beginning to hatch, and steadily fall off from there until most flies are dead by mid to late August, and he stated the flies do not make the migration with the birds.

But, since these flies don’t lay eggs, they must be spending the winters in the nest boxes as pupae, awaiting the return of their hosts year after year. Hutson found that males are more prevalent early in the spring, with females to follow. This leads us to an interesting question of how this louse fly got onto this bird! The fly was already aboard the bird when it entered the box (if you watch closely you can see a white blob that moves around neck is first visible at 0:06, immediately after the male bird approaches the sitting female). This means that one of two things happened: either the male bird has in fact carried its little parasite friend down to Africa and back (something that neither Hutson nor Walker & Rotherham (2010) believe to be the case) (and assuming this was the first nestbox that the bird stopped in, which I take to be the presumption of the ornithologists who posted the video and stated it shows a male reuniting with its mate from last year in last year’s nestbox), or alternatively, the male bird did stop for a time in another nestbox where it picked up its little hitchhiker, and then proceeded on to its longterm mate. This of course raises questions about how committed these birds really are to their mates, and whether they may be getting a little action on the side (or at least exploring their other options) before settling down for the season. Since I know pretty well nothing about bird biology, if someone knows more about swift mating, bonding, and extra-pair copulation, let me know in the comments if I’m way off.

Either way, catching a glimpse of a louse fly playing peekaboo on the neck of its host may raise more questions than the initial emotional response of “WHAT IS THAT THING?!?”, and that’s pretty darn cool.

Who’s really pollen their weight: Bees, or Flies?

Biology, Diptera, Environment, Publication 5 Responses »

Apr 222015

March flies (Bibionidae) pollinating both flowers and each other.

March flies (Bibionidae; Bibio albipennis) pollinating both flowers and one another.

When it comes to pollination ecology research, bees are their own knees. Along with butterflies, birds, and bats, bees reign supreme as the queens of pollinator studies, with huge amounts of money and time spent each year trying to understand everything about their biology, from how they choose which flowers to visit, to the structure of their societies, and of course, why some species seem to be in decline. While some flies (like flower flies — family Syrphidae) are beginning to break into the hive of pollination research, bees so dominate the pollination ecology landscape that suggesting alternative groups, like other flies, may also be important pollinators can result in quizzical looks, derisive scoffs, and even disbelief at results that run counter to popular thinking.

The latter is exactly what happened when Dr. Katy Orford submitted a paper from her PhD that showed flies play a major role in grasslands pollination; the editor rejected it due to a lack of literature supporting her Dipterous conclusions. So, Orford set out to do what no one had done to this point: show beyond a shadow of a doubt that flies are important, and overlooked, pollinators.

Crane fly hanging out among the flowers.

Crane fly (Tipulidae) hanging out among the flowers.

Orford began by gathering and assembling previously published datasets that looked at the connections between pollinators and plants across the UK, specifically datasets that looked at plant-pollinator-visitation networks (what insects visit which plants based on observations) and pollen-transport networks (how many grains of each kind of pollen was found on each insect’s body). Orford immediately found that few studies had actually looked at these metrics for entire insect communities rather than just targeted groups like bees, but she ended up with a dataset spanning both natural and agricultural ecosystems that included over 9,000 insect specimens, 520 pollinator species, and 261 species of plants.

With her dataset in hand, Orford had four questions she wanted answered: how specialized are flies with regards to the plants they pollinate; how prevalent are dipteran pollinators in agriculture and how much pollen are they carrying; and most importantly, how do flies stack up against bees, butterflies, and beetles when it comes to transporting pollen?

Flies, it turns out, aren’t overly picky about what flowers they’ll visit and feed from. While flower flies visited a broader spectrum of the floral smorgasbord available in the study plots, they were found to be no better at transporting specific pollen species than the other fly families. This isn’t to say that there aren’t any specialized relationships between plants and flies (cacao and biting midges in the genus Forcipomyia being the most famous example of flowers and flies being in league with one another, much to our enjoyment), only that in the particular environments Orford examined she found no evidence for specialization among the residents.

When Orford looked at the composition of fly visitors on farms, non-syrphids were not only more speciose than their flower fly cousins, averaging 7 species to 3, respectively, but they also outnumbered them 4 to 1 in the sheer number of individuals. In fact, Orford found that only 3 farms out of the 33 she had data for reported more flower flies than other flies. Not only were non-syrphids more diverse and more abundant, but they also carried more than twice the number of pollen grains on their bodies as flower flies did in agricultural fields. All of this suggests that the role of syrphids in pollination ecology, a topic that has received at least some study at this time, may only be the tip of the iceberg when considering the importance of flies in agricultural pollination.

Urophora affinis (Tephritidae)

This is all well and good when deciding which flies are better pollen bearers among themselves, but how do they stack up against the rest of the competition? Do bees really pull their weight in the great pollen wars, or have flies been shouldering the load without us realizing it?

Unsurprisingly, bees are really good at carrying pollen. Not counting the pollen trapped in their specialized storage structures (like the corbicula of Apis mellifera, or the scopa of Megachilidae leaf-cutter bees), Hymenoptera still beat out all the other insect groups when the number of pollen grains on each individual was counted, while flies, butterflies and beetles were all found to be roughly equal in their carrying capacity. This result shouldn’t really come as a surprise, as bees have specialized branched hairs all over their bodies that have evolved to efficiently trap pollen, which is then combed out of the hairs and into their pollen storage structures. So while flies are usually pretty hairy, they’re essentially catching pollen with a comb, rather than the hair net that bees are employing.

But, while each individual bee may carry more pollen than each individual fly, Diptera are much more abundant, at least in agricultural settings. In fact, Orford found that two-thirds of all pollinating insects recorded in her agricultural datasets were flies. That means that when we talk about agricultural pollination ecology, which is predominantly focused on bees currently, we’re a long ways from seeing the complete picture.

Perhaps Wired’s editors were on to something here. If it looks like a bee, and carries pollen like a bee…

There was one other thing that Dr. Orford discovered, however. When she broke down her pollen-load data beyond just Hymenoptera and Diptera, and started looking at the pollen loads of bees and flies on a finer taxonomic scale, she found that, statistically speaking, flower flies carry just as much pollen on their bodies as European honey bees.

Does this mean flower flies are as effective pollinators as honey bees? It’s too early to say; honey bees may be better at transferring pollen from flower to flower and causing flowers to develop seeds; or they might not be. More research into the pollination efficiency of flies is clearly needed, but the potential implications of this pollen equality are staggering. Orford’s data shows that on farms, flower flies make up about 16% of all flower-visiting insects, while bees, butterflies and beetles together combine to make up only 33% of visitors. It’s very possible that we’ve been attributing a little too much success to those “busy” little bees.

Orford’s work presents another fly in the ointment, so to speak: if bee populations, including honey bees, are indeed declining as has been suggested by several recent papers and hyped by the media and special-interest groups like beekeeping societies, what’s happening with flies? Are they experiencing similar declines as social bees, or are they shielded from the effects of human-trafficked diseases and parasites, along with pesticide accumulation in hives by their solitary and undomesticated lifestyle? Are monocultural agriculture practices and denuded, degraded, and destroyed natural habitats reducing fly diversity in the same way that other pollinators appear to be experiencing? We just don’t know at this point.

And while bees become an increasingly popular talking point and agenda item for politicians, Diptera remain undiscussed. US President Barack Obama in particular has become a champion for bees, with a pollinator garden and bee hotels supposedly being built on the grounds of the White House. Why not monitor and speak up for all of the pollinators, two-winged or four, in President Obama’s backyard as Dr. Orford did?

Geron sp. (Bombyliidae)

Well, as she notes in the conclusions of her work, flies aren’t as easy to study as bees are. For one, flies don’t return to a predictable location such as a hive or nest like bees do, which makes observing and experimenting with them considerably more difficult. The other major issue, of course, is taxonomy. There are more than 6 times as many species of fly currently known than there are bees, and those flies are notoriously difficult to identify, even to the proper family in some instances, never mind trying to determine genus or species. While the flower flies have received a great deal of taxonomic attention in the past 50 years, and are generally more easily identified than most groups of flies, the same is not true for the top non-syrphid pollen carriers identified by Dr. Orford: Bombyliidae, Muscidae, and Calliphoridae, all of which pose significant identification and/or taxonomic challenges at the moment.

The solution? From Dr. Orford: “training in dipteran taxonomy should be more available to ecologists. Alternatively, specialist taxonomists should be included in research projects to prevent pollination biologists being deterred from recording Diptera due to identification difficulties”.

I couldn’t agree more.

Dipterists around the world are working hard to make the flies they’ve devoted their careers to more accessible, both through the publication of identification resources, and through the organization of workshops and other educational events. However, as has been shown by Dr. Orford’s work, we should expect a growing demand for keys and other identification tools, along with the people who create them, to usher in a new era of pollination ecology; an era defined by a greater understanding of pollinators of every ilk through collaboration and communication between Diptera taxonomists and pollination ecologists.

As for Dr. Orford, since successfully defending her PhD last fall, she’s taken a position working with government policy in the UK, providing an important voice for flies alongside those advocating for more “traditional” pollinators. As for her paper on grasslands pollination, whose initial rejection inspired this long-overdue look into the flowery lives of flies, now that she’s shown the pollination hivemind the importance of Diptera, she hopes her work will fly through the peer-review process.

Toxomerus marginatus (Syrphidae)

Orford K.A. & J. Memmott (2015). The forgotten flies: the importance of non-syrphid Diptera as pollinators, Proceedings of the Royal Society B: Biological Sciences, 282 (1805) 20142934-20142934. DOI: http://dx.doi.org/10.1098/rspb.2014.2934

It’s Pí Day!

Diptera, Fun Stuff, Pop Culture 2 Responses »

Mar 142015

It’s March 14, 2015, which, in North America at least, makes it Pi Day (3/14/15), a day where people celebrate the most well-known mathematical constant with delicious baked goods and puns.

But in Middle-earth, the magical and engrossing world created by J.R.R. Tolkien as the setting for his tales of rings, hobbits, and adventure, Pi Day could coincide with the elven celebration of the Diptera! In Quenya, the ceremonial language of the high elves in Middle-earth, the word “fly” (in the entomological sense) translates directly to pí.

Translation and Tengwar courtesy of Lee Jaszlics (biologist, photographer, and Quenya aficionado)

Coincidentally, flies actually make their debut in the world of Middle-earth on March 15, 3019 (The Return of the King, Book Six, Chapter II – The Land of Shadow) as Frodo and Sam wander through a riverbed deep within Mordor. Tolkien writes:

To their surprise they came upon dark pools fed by threads of water trickling down from some source higher up in the valley. Upon its outer marges under the westward mountains Mordor was a dying land, but it was not yet dead. And here things still grew, harsh, twisted, bitter, struggling for life. In the glens of the Morgai on the other side of the valley low scrubby trees lurked and clung, coarse grey grass-tussocks fought with the stones, and withered mosses crawled on them; and everywhere great writhing, tangled brambles sprawled. Some had long stabbing thorns, some hooked barbs that rent like knives. The sullen shrivelled leaves of a past year hung on them, grating and rattling in the sad airs, but their maggot-ridden buds were only just opening. Flies, dun or grey, or black, marked like orcs with a red eye-shaped blotch, buzzed and stung; and above the briar-thickets clouds of hungry midges danced and reeled.

The dancing midge clouds are easily explained, but I spent a lot of time trying to find a fly species that would fit Tolkien’s description. It turns out that “dun or grey, or black, marked like orcs with a red eye-shaped blotch” is a surprisingly rare combination in the Diptera. In fact, I couldn’t find any species of flies that could be described as dark with red splotches! Certainly there are species that are dark with red heads, including micropezids in the genus Scipopus, or signal flies in the genus Bromophila (as recently discussed by Piotr Naskrecki), and many flies are known for literally having red eyes (think of your friendly kitchen Drosophila), but unlike beetles, red blotches or spots seem to be rare in flies.

Scipopus sp. from Bolivia

The only solution I could come up with that fit the general description and habitat of these Morgai flies was perhaps a species of Chrysopilus snipe fly (Rhagionidae), commonly called golden-backed snipe flies here in regular Earth. These flies have a blanket of magnificent golden pile on the top of their thorax, which can be brushed off giving the appearance of the Eye of Sauron (although they are certainly not blood suckers or pests). Perhaps under the evil influence of Sauron, a new species of Chrysopilus arose in Morgai, developed a taste for orc blood, and took to the air to reign terror from the skies.

Chrysopilus thoracicus from Ontario on the left, with its Tolkienian cousin Chrysopilus “morgai” on the right

So on this Pí day, I hope you’ll not only herald the popular mathematical constants, but also the dipteran variables that make our natural history interesting, and our literary history magical.

Of course, the best possible way to celebrate would be to follow James Gilbert’s lead and make a Pí Pie for Pi Day. Mmmm, pie.

A Syrphus ribesii pork pie I made earlier #bakeyourstudyspecies – mimicry didn't help it that evening @SensoryEcology pic.twitter.com/saXqFuCEuU

— James Gilbert (@james_gilbert) March 11, 2015

Footnote: In the recent video game Middle-earth: Shadow of Mordor, Morgai flies were depicted as eusocial, living in paper hives, and able to drive off nearby orcs with a well-placed arrow. While I may be taking liberties with fly evolution to make a red, blood-sucking snipe fly, calling what are clearly social wasps “flies” gives WB Games a taxonomy fail index of 58. Now there’s some math for you.

Black Fly Day? How about Cyto Monday!

Cool Science, Diptera, Taxonomy 3 Responses »

Nov 282014

When identifying insects, the further you want to identify them, generally the smaller the morphological characteristics you need to look for are. For instance, to recognize the taxonomic order Diptera, you need only count the number of pairs of wings an insect has (usually…), but to identify a fly to species, you may need to hone in on the presence or absence of a single bristle on its thorax, or middle leg, or genitals. But what about species or populations where even these characters may be too similar to confidently tell distinguish, and where you could potentially be overlooking and unknown amount of diversity, better known as the elusive cryptic species? Well, you could look at their DNA, and try to see if there are any differences there, or, if you work on black flies, you could literally look at their DNA. Like, actually looking at the shape and patterning of their chromosomes, specifically special clumps of DNA found in larval black flies called polytene chromosomes.

Polytene chromosomes are the jumbo-sized versions of normal chromosomes only found in cells involved with secretion, and for whatever reason, are only present in springtails (Collembola) and true flies (Diptera). Rather than replicating and then splitting themselves up amongst a series of daughter cells like normal chromosomes, polytene chromosomes replicate themselves over, and over, and over again, sticking together in clumps of hundreds to thousands of complete chromosomal strands all woven together into a thick rope of genetic instructions. By banding together like this, these special chromosomes reveal all kinds of fascinating information about species and speciation.

Starting in the 1930’s, while scientists were only just beginning to understand what chromosomes were and the role they played in genetics and heritability, dipterists began to notice that polytene chromosomes provided an untapped source of morphological characters to work with. Black fly taxonomists in particular latched onto this new dataset, largely because these over-sized chromosomes were easy to find in the silk glands of larval black flies, and provided a simple and low cost means of identifying species. Patterns of black and white bands, the locations and sizes of bulges, blisters, and rings of Balbiani all appeared to be conserved within populations and species, and with only 3 chromosomes to deal with, taxonomists, already tuned to look for the slightest differences and similarities between specimens, began to find all kinds of useful information; specific banding patterns that would be inverted in some species, but not in others; whole arms of chromosomes getting spliced onto the “wrong” chromosome; all three chromosomes getting jumbled up and stuck together in the middle like a genetic pinwheel with what they called a chromocenter.

By studying these “macrogenomes”, Simuliidae experts have been continuing to refine what a black fly species really is, and are beginning to unlock the mysteries of cryptic diversity.

Take, for example, work recently published by a group of black fly experts on the Old World subgenus Simulium (Wilhelmia). These flies originally came to the group’s attention due to an outbreak of black flies in Turkey which was driving down livestock production and tourism due to the sheer numbers of biting adults (those in Northern Canada can surely commiserate), and in order to figure out what species was responsible, decided to take a closer look. A much, much closer look, specifically at their polytene chromosomes.

After sampling larval black flies from across Europe, they discovered that what had recently been considered one generalist species found from England clear across the continent to at least Kazakhstan, Simulium (Wilhelmia) lineatum, was actually at least 3 species, each with unique differences in their chromosomes, and which replaced each other in streams as you head East!

Here you can see where the “actual” Simulium lineatum is found (blue) (although the authors note that something funny may be going on with the English specimen’s chromosomes, which could lead to further splitting), and where each additional species crops up as you move east, with Simulium balcanicum in green, Simulium turgaicum in red, and Simulium takahasii in yellow. The orange area without any data points is a void in the team’s data, but they have reason to suspect that several species recently described from China will fit into the pattern discovered in the west. Now that the team has worked out these basic limits for each species, they also hope to explore whether or not these species may be successfully mating with one another despite the differences in their chromosomes, or whether hybridization can occur between species pairs. All of this new information will in turn help us understand the intricacies of polytene chromosome taxonomy further, and continue to adapt black fly taxonomy to fit the total evidence available.

So by peering deep within the silk glands of black fly larvae, we can now weave together the ways in which simuliids diversified, and begin to understand the web of underlying mechanisms that make one species become two, or three, or more. It just goes to show that literally no matter how closely you look, there will always be surprises waiting to be found when it comes to fly taxonomy.

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Adler P.H., Alparslan Yildirim, Onder Duzlu, John W. McCreadie, Matúš Kúdela, Atefeh Khazeni, Tatiana Brúderová, Gunther Seitz, Hiroyuki Takaoka & Yasushi Otsuka & (2014). Are black flies of the subgenus Wilhelmia (Diptera: Simuliidae) multiple species or a single geographical generalist? Insights from the macrogenome , Biological Journal of the Linnean Society, n/a-n/a. DOI: http://dx.doi.org/10.1111/bij.12403

Adler, P.H., Currie, D.C., Wood, D.M. 2004. The Black Flies (Simuliidae) of North America. Cornell University Press. Ithaca, NY & London, UK. 939 pp.

Jurassic World Job Ad: Entomologist Wanted

Diptera, Insects, Pop Culture, Rant 4 Responses »

Nov 252014

The trailer for Jurassic World, the latest instalment in the Jurassic Park franchise, was released today, and well… see for yourself.

While scientists have apparently figured out how to genetically modify dinosaurs (which I thought was the entire premise of the original when they spliced frog DNA into ancient Dino DNA, but whatever, GM-OH NOES!), they still haven’t hired an entomologist to tell them which amber inclusions are mosquitoes (family Culicidae), and which are crane flies (family Tipulidae).

Oops.

No big deal though, crane flies and mosquitoes are close enough, right? Well, actually they’re about as closely related to one another as velociraptors are to sea turtles (and only a little more closely related than humans are to Tyrannosaurus rex).

I think we can all agree that Jurassic World would have a much different mood if it climaxed with this

than it does with this

So for all you Hollywood producers out there looking for an entomology consultant to save you from embarrassing oversights, have your people call my people; we can fix this. But in the meantime, save me a seat when Jurassic World hits theatres.

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P.S. About that Mosasaur. While we know marine mammals like killer whales can be bitten by mosquitoes (a captive killer whale in San Antonio contracted and later died of West Nile Virus back in 2007), the odds of a mosquito biting a wild mosasaur in the ocean, and then flying, fully leaden with blood, back to shore, only to be immediately entombed in sap running down a tree trunk and preserved for a few million years as an amber inclusion, are a bit of a stretch.

There’s a chance I may be overthinking this.

Two new flies to die for. Or not.

Biology, Diptera, Natural History, Taxonomy, To Know A Fly 1 Response »

Oct 142014

Cyanide: poison of choice for jilted lovers, mystery writers, and entomologists alike. But we’re not the only ones to employ this potent potable in our chemical arsenal; polydesmid millipedes have been defending themselves with cyanogenic compounds for millions of years.

Of course, when one organism figures out a new way to protect itself using something that kills lesser creatures, it’s usually not long until somebody else evolves the ability to capitalize on that protection, even when it’s something as deadly as cyanide. Enter 2 new species recently described by John Hash of UC Riverside, Megaselia mithridatesi and Megaselia toxicobibitor, the Rasputins of the scuttle fly world.

Megaselia is an immense genus of Phoridae with a wide diversity of natural histories, so it’s perhaps no surprise that something like cyanide-siphoning could show up here, but that doesn’t reduce the magnitude of such a finding. But how does one go about associating tiny flies unknown to science with murderous millipede defenses?

John works primarily on another genus of scuttle fly that’s also associated with millipedes, Myriophora. Rather than stealing cyanide, these flies prefer to parasitize millipedes protected by another noxious chemical family, benzoquinones. To find these flies, he stresses the millipedes a little by shaking them in a paper towel-lined plastic tube hard enough to piss them off, but not enough to cause physical damage, leading them to exude their defensive chemicals onto the paper towel. John then laid out these poisoned paper towels, and sometimes tied up the annoyed millipedes like the sacrificial goat in Jurassic Park using dental floss, and waited for the flies to come in to the bait. While John was expecting to find new Myriophora species and associations, he states in his paper that discovering a Megaselia/millipede association was a golden example of serendipity in science.

With specimens and natural history notes in hand, John returned to the lab and gave these 2 new species especially fitting names; mithridatesi is an homage to King Mithridates IV of Pontus, who famously immunized himself to a variety of poisons by consuming them in small, sub-lethal quantities, and toxicobibitor, which literally translates to “poison drinker” from Latin.

If you want to hear more about John’s work, and see millipedes on dental floss leashes, check out this video from the Natural History Museum of Los Angeles County, which was filmed while John was down helping out with the Zurqui All Diptera Biodiversity Inventory in Costa Rica. It was while he was here, surrounded by dozens of other dipterists, that he discovered the poisonous habits detailed in this paper. That certainly makes for a killer field trip if you ask me, even without the cyanide.

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Hash J.M. (2014). SPECIES OF MEGASELIA RONDANI (DIPTERA: PHORIDAE)
ATTRACTED TO DEFENSIVE COMPOUNDS OF CYANOGENIC
MILLIPEDES (DIPLOPODA: POLYDESMIDA), Proceedings of the Entomological Society of Washington, 116 (3) 273-282. DOI: DOI: 10.4289/0013-8797.116.3.273

If you’re curious, I asked Millipede Man Derek Hennen about the biology of cyanide-laced millipedes, and he provided a few references and info.

Adventure Time Awaits

Diptera, Entomology, Life as a Grad Student, Travel, Trip Report No Responses »

Aug 052014

It’s been a busy couple of weeks for me since my qualifying exams. I’ve travelled up to Ottawa a few times to work with my co-advisor and gather a big, new DNA dataset, I’ve put my Google-fu and Google Translate skills to the test, and I’ve learned how spoiled I am by the ease of booking hotels in North America.

All of that hard work is about to payoff though, as I’m heading out for a grand European tour! Starting with a red-eye flight Tuesday evening, I’ll be attending the 8th International Congress of Dipterology (ICD8), and spending 2 weeks on the roads and in the natural history museums of Europe.

This is the second ICD I’ll have attended, and just like the last one in Costa Rica, I’ll be blogging all the way through about the things I learn, experiences I have, and whatever else comes up. I’ll also be tweeting, Instagramming & Vine-ing my way across the continent afterwards as I visit natural history museums and entomology collections looking for important type specimens of Micropezidae described by some of entomology’s biggest names over the past 250 years.

Starting with a quick stop in Iceland to explore, I’ll move on to Copenhagen to visit the Natural History Museum of Denmark, and then will be driving down to Potsdam, Germany to present my newly acquired data at ICD8 and fill my head with all kinds of new knowledge about flies & dipterology. After that I’ll be hitting the road with fellow PhD student & blogger Kai Burington to visit museums in Stuttgart, Munich, Vienna, Dresden, Berlin, and Muncheberg before heading back to Denmark to visit friends and fly home.

Before things kick off, I’d like to thank the Smithsonian Institute and the S.W. Williston Diptera Fund for making this trip possible for me with a Diptera Research Grant. If you’d like to help make future opportunities like this possible for graduate students like myself or others interested in dipterology, I’d encourage you to donate to the S.W. Williston Fund. You can find more information about S.W. Williston and the Smithsonian endowment fund program here.

It’s going to be a whirlwind trip, and I hope you’ll join me as I try and share my European adventure with you.

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