Environment » Biodiversity in Focus Blog

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

Monikers Only Matter for Vertebrates

Blogosphere, Environment, Invertebrate, Taxonomy 6 Responses »

Jan 042015

In the latest issue of Scientific American, David Shiffman has a short article titled “Monikers Matter“, on the potential importance of common names for the conservation of species. He highlights the case of Charopa lafargei Vermeulen & Marzuki, a species of recently discovered snail only known from a single hill in Malaysia which is slated for demolition by the cement company Lafarge. He also cites a 2012 study by Paul Karaffa et al. that examined how student’s value animals based solely on (fictional) common names, and found that patriotic or “positive” names resulted in the students being more willing to conserve those species. It’s an interesting idea, and might be something for taxonomists to consider.

But, every species name put forward in Karaffa et al.’s study was either a mammal or a bird. Do we really think the same principles will apply for all species equally, specifically the uncharismatic invertebrates like insects, snails and their overwhelmingly diverse brethren?

There are 3 species listed as Endangered or Critically Endangered by the IUCN which have a common name that includes the term “American” (a term that features heavily in the positive section of Karaffa et al.’s survey), 2 of which are found in the USA (the 3rd is a Central American frog). Conveniently for this comparison, one is a vertebrate, the American Eel (Anguilla rostrata; listed as Endangered), and the other an invertebrate, the American Burying Beetle (Nicrophorus americanus; listed as Critically Endangered).

To estimate how much society values the conservation of these 2 species, I simply entered their scientific species names into Google Scholar and restricted the results to papers published in 2014, with the assumption that the number of people actively studying a species should act as a pretty good approximation for the value we place on that species as a society. In 2014, there were at least 456 papers published discussing the American Eel. In comparison, there were only 26 papers discussing the American Burying Beetle.

Obviously there is more at work here than just common names, but the fact that we value (by this simple metric at least) the American Eel so much more than the American Burying Beetle (a factor of 17.5x more) suggests that monikers don’t really matter, unless of course you share a spine with the species.

Vertebrate and charismatic bias is a significant influence in conservation biology, and nomenclature is unlikely to be an easy fix for it.

—
Karaffa P.T. & E. C. M. Parsons (2012). What’s in a Name? Do Species’ Names Impact Student Support for Conservation?, Human Dimensions of Wildlife, 17 (4) 308-310. DOI: http://dx.doi.org/10.1080/10871209.2012.676708

Vermeulen J.J. & Marzuki M.E. (2014). ‘Charopa’ lafargei (Gastropoda, Pulmonata, Charopidae), a new, presumed narrowly endemic species from Peninsular Malaysia, Basteria, 78 (1-3) 31-34. DOI:

Beware: Irony Contained Within

Environment, For a Good Cause, Rant No Responses »

Jan 232014

Seeing how Canadian Prime Minister Stephen Harper has suddenly become a bastion for conservation biology, ornithology and science outreach with the announcement that a bird sanctuary has been named in his honour in Israel, I put together a little memento for him to hang in his office. Hopefully it will serve to remind him just how awesome birds and nature are, as long as they aren’t getting in the way of his Albertan oil field development plans, of course.

All kidding aside, the fact that another country thought that it was appropriate to bestow an honorary doctorate on and name a scientific research facility after a man who has been on a not-so-subtle campaign against scientific research & evidence-based policy making in Canada for the past 8 years is an absolute farce.

I guess in the end the joke is on me though. I’m the one spending the prime of my life fighting against the anti-science rhetoric being spewed by my elected officials to earn a PhD the old-fashioned way instead of just dismantling research divisions, field stations and libraries that don’t support my political platform!

Yep, he sure showed me…

Mammoths of the South Pacific: Did Humans Drive A New Species of Black Fly to Extinction? #BlackFlyDay

Biology, Cool Science, Entomology, Environment, Insects, Taxonomy No Responses »

Nov 292013

On the island of Raivavae, one of the Austral Islands in the middle of the Pacific Ocean, buried deep beneath the surface of a swamp in mud accumulated at the foot of a stream for thousands of years, scientists have found all that remains of a unique new species of Black Fly (Simuliidae): larval head cases left behind when the flies molted into pupae. These subfossils, not yet hard and mineralized like conventional fossils yet still preserved in near-perfect condition by the mud, not only raise the question of how a tiny little fly found its way to an island in the middle of nowhere, but also provide the only evidence of a murder mystery 2 million years in the making.

The missing species on Raivavae is Simulium Inseliellum raivavaense, recently described by Douglas Craig of the University of Alberta and Nick Porch of Deakin University in Australia, from material collected in 2010. Despite the subfossil larval head capsules being the only “specimens”, Craig & Porch were able to determine S. I. raivavaense was a new species based on the shape, position, and number of teeth on the hypostoma, essentially the lower lip of a black fly larva’s mouth.

Black Out Speak Out

Environment, Rant 6 Responses »

Jun 042012

Prime Minister Stephen Harper’s War on Environmental Science

I don’t normally wade into discussing politics because 1) I don’t follow it as closely as perhaps I should and, 2) it can be a pretty controversial topic which can get messy in a hurry. I don’t want to weigh this week’s flypaper down too much, but I feel compelled to share a number of deeply concerning developments in the Canadian government’s recent cuts to environmental research.

The Environmental Lakes Area, a world-class facility studying the affects humans and our products have on freshwater ecosystems, is being closed down.

If we’re not studying the affects of pollution on freshwater ecosystems, I guess we can still keep track of pollutants in marine environments. Wait, you mean that entire department has been cut as well? Oh. (As a slightly ironic aside, even the US media is picking this one up and questioning what the hell Canada is thinking)

Well, certainly our protected terrestrial environments will be studied and Canadian National Parks kept safe. No?! You have got to be kidding me. (It’s not only the natural history aspects of Parks Canada getting cut, it’s also our cultural history.)

Add to this the thousands of jobs cut across the Canadian Food Inspection Agency, Agriculture & Agri-Food Canada, Environment Canada, Public Health Agency of Canada and Health Canada, and it’s not hard to see that our current government views scientists & environmental research as an inconvenient truth (especially when they don’t tow the party line).

I’m incredibly proud to call Canada my home & native land, but am utterly ashamed of these “cost saving” measures being rapidly pushed through by the Conservative government. These short-sighted cuts will have long-lasting environmental ramifications well beyond the tenure of any political party’s leadership, will tarnish Canada’s reputation as an environmentally-friendly nation, and will hamper our ability to attract new minds to our universities, industries and governments. I have no doubt that in 10-15 years we will look back on this government and wonder “O Canada, what have you done?”

It’s World Tapir Day!

Environment, Nature 5 Responses »

Apr 272012

Yes, World Tapir Day is a real thing. No, you don’t get the day off work.

As consolation, enjoy this photo of a juvenile South American Tapir (Tapirus terrestris) from Ecuador.

All four species of tapir (3 spp. in South America, 1 in southeast Asia) are currently listed as vulnerable or endangered on the International Union for Conservation of Nature’s Red List. The South American Tapir has the largest range of all tapirs, spanning the majority of the Amazon river basin, yet is still under threat from habitat destruction and poaching.

Tapir’s are usually difficult to see in the jungle, preferring to go about their business through the night. So how did I get a close up photo in the middle of the day? The research station I was working at had adopted her¹ after her mother was killed by the local Huaorani tribe², and thus she was quite friendly, coming right up to greet our group when we arrived. Later in our visit, she nearly gave me a heart attack when she came thundering out of the jungle looking for attention while I was looking at a fly. Needless to say, I nearly spread some extra fly bait that day…

————————

1 – While my tapir-sex-identification-skills are a little rusty, I recall being told by the staff that this was indeed a young female.

2 – While the station is situated within Yasuni National Park, the indigenous Huaorani people are allowed to continue their traditional way of life. Unfortunately, the Huaorani have found an easier way to go about life; by selling bushmeat and live animals destined for the pet trade at market in the nearest cities. The research staff went so far as to paint their rescued tapir with bright white paint to try and deter the locals from killing it, though the tribe made no promises about it’s potential fate.

Tuesday Tunes – Butterflies & Hurricanes – Muse

Entomology, Environment, Pop Culture, Tuesday Tunes No Responses »

Sep 062011

As hurricane season arrives and dangerous storms approach the east coast of North America, it’s worth considering what causes these deadly cyclones. Not necessarily the warm waters off of Africa, but perhaps a butterfly on the other side of the world, whose flapping wings have set off an unpredictable set of events. Although the butterfly effect (as it relates to chaos theory, not that questionable Ashton Kutcher movie) may not be totally responsible for storms causing billions of dollars damage annually, the idea that simple atmospheric changes made by a flying butterfly can impact the total world is quite astounding.

Now to make you really think: as species become threatened with extinction thanks to human activity, how might a reduction or lack of these small atmospheric changes affect future weather patterns and civilization? Fewer storms? More? Who knows.

All joking and theorizing aside, if you or those you know live in places prone to hurricane or cyclone activity, please be safe in the coming weeks.

This song is available on iTunes – Butterflies and Hurricanes – Absolution

Tuesday Tunes & Trends – Bed Bug Edition

Entomology, Environment, Tuesday Tunes 12 Responses »

May 172011

Ryan Fleacrest sometimes hangs with Michael Bubonic

Normally I have a bit of fun with Tuesday Tunes, whether mocking sugary pop music or giving props for mad entomological rhymes. Today however, I want to share a few trends which are both topical and disheartening (don’t worry, I still have a great song for you at the end of the post).

Last week, a report came out of Vancouver in which doctors reported bed bugs harbouring antibiotic resistant bacteria (Staphylococcus aureus [MRSA] and Enterococcus faecium [VRE]). While it’s a scary proposition, it’s unknown whether the bed bugs are capable of transferring the bacteria at this point. As Jonathan Eisen points out, it shouldn’t be too much of a surprise that MRSA was found; bed bugs are ectoparasites and MRSA is primarily a skin/wound-related infection. In fact, bed bugs have never been shown to transmit diseases (bacterial or viral) despite plenty of research attention, and as far as I can tell, have never been implicated in a human death. More people have died from improper handling and use of pesticides intended to kill bed bugs than from the bed bugs themselves!

Ants & Architecture

Environment, Photography, Travel 9 Responses »

Mar 102011

The wife and I took a weekend off last month and headed down to Chicago to visit a friend, take in the sights, and enjoy a bit of a break. I must say that Chicago was one of the coolest big cities I’ve been to, with great architecture, plenty of great food (including the best pizza ever), and a first class entomological exhibit!

Yep, that's a live ant colony within the title sign, a great way to start an exhibit!

The Chicago Field Museum is currently exhibiting “The Romance of Ants“, which follows the life and career of resident myrmecologist Dr. Corrie Moreau. I had the chance to hear Dr. Moreau discuss her research during a recent visiting scientist seminar here at Guelph, so it was great to see and read about her career path. Did I mention that her entire entomological life was illustrated as a comic book? Because it is, and it is awesome!

The formicid scent trail leads through an excellent comic

You might recognize some familiar ant photos from the entomological blog-o-sphere: sprinkled between the comic frames were huge reproductions of Alex Wild’s fantastic photographs. The huge printing of these photos looked great, and really added to the feel of the exhibit by making you feel as if you were a part of the colony!

Art & Science as one

Overall it was a great exhibit, but I worry its position in the museum will cause a lot of people to miss it. Located in a dark corner room which looked like an old Western saloon on the outside, we were the only two in the exhibit for the entire 15-20 minutes it took to take in. The museum wasn’t overly busy despite being a Saturday morning, but there were quite a few people who I saw walk straight on by without recognizing that a great blending of science and art was lying only a few feet away (kind of like ants in everyday life). The exhibit is scheduled to run through the end of 2011, so if you’re in the area, I’d highly recommend checking it out!

I played tourist this trip and tried my hand at some architectural photography while we walked around town. Downtown Chicago features some really amazing architecture and sculptures, which made my attempts a little easier. It’s certainly a different style of photography than I’m used to, but it was great getting a few clicks in again!

Lunar Eclipse of the Blog

Environment, Nature, Photography No Responses »

Dec 212010

EXIF - 1.6 sec, f/5.0, ISO 400, 70-300mm lens set at 122mm, tripod+remote shutter release

Happy Winter Solstice! It might not be as exciting as Christmas, but the winter solstice signals the lengthening of days, shortening of nights, and the return of summer and insects. Ya, it might be awhile still, but a guy can dream can’t he?

This year also saw a rare occurrence of a full lunar eclipse occurring on the winter solstice. Does it mean anything? Nope, just a special day for a special occasion. Since the next time these two astrological events coincide is in exactly 84 years on Dec. 21, 2094, it would have been a nice time to do some moon-gazing! Of course if it occured at 3am EST on a cloudy night and you have a committee meeting the next day like I did, you had to settle for photos you took in years past!

This shot was from the lunar eclipse of February 2, 2008 and shot from the middle of a rural road north of Guelph. Getting away from the light pollution of cities is the first step in astrophotography. A tripod, a remote shutter release (or warm mitts to guard against the cold while you press that button) and a hot drink all help to get the shot. Unless you live in Western Africa or the South Pacific, you’ll have to wait until June 2012 to try your hand at photographing the next partial lunar eclipse!

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