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Celebrating FLYTREE

Monday, March 28th, 2011

A toast, everyone, to flies and phylogeny!

An international team led by NCSU’s own Brian Wiegmann has been hard at work assembling the tree of life for flies (Diptera) for the last 7 years or so. The project was funded by the National Science Foundation in 2004 as part of their ATOL (Assembling the Tree of Life) initiative. This month, the results were finally published online in the journal Proceedings of the National Academy of Sciences, USA (link). A story based on the NCSU press release can also be found here.

Although some results echoed previous work, there were some surprises. First of all, the weird family of mountain midges (Deuterophlebiidae) turned up as the sister group to all other flies. That means that these strange flies have not shared a common ancestor with other flies for probably more than 250 million years! Mountain midges have a humpbacked appearance, with a small head and very long antennae. Larvae live in fast-flowing mountain streams, and have suckers on each of their prolegs to hold fast to rocks in exposed current. Here’s a couple images of two of our voucher specimens:




The next-branching family is one just as bizarre, the family Nymphomyiidae. These tiny flies live next to swift streams, and adults have fringed wings that often break off. Here’s the best picture I could get of our voucher specimen:

[here's a much better picture of a Japanese species]
[also, take a look at this great article in FlyTimes]

The other oddballs that have me excited are the bee louse (Braulidae) and a family of scale insect parasitoids, Cryptochetidae. These families were always hard to place, but we found good evidence that they are actually close cousins to the laboratory Drosophila! Check out these weird, crazy flies:

bee louse (Braulidae)

bee louse (Braulidae)

bee louse (Braulidae)

Cryptochetidae

OK, that’s enough show & tell. If you want to learn more, you’ll have to read the paper.

Insect of the week – number 57

Friday, February 4th, 2011

Ochthera tuberculata

My Favorite Flies: Stenomicra

Wednesday, December 22nd, 2010

Can flies be cute? Yes, definitely! Take, for instance, Stenomicra angustata:

Stenomicra angustata, from Raleigh, N.C.

For one thing, this guy is tiny – just over one millimeter. It took me a while to find this one in the vial to take a picture. Then there is the nicely contrasting yellow and brown coloration.

I’ve collected this cute little fly only a couple times. The first time was sweeping through rushes and cattails at the edge of a small pond in a suburban park. The one above came from a malaise trap next to a cornfield on the NCSU farm. S. angustata is found across eastern North America, from Texas and Florida to Wisconsin and Quebec, but it is in fact the only Nearctic species of a large, pantropical genus.  There are only about 26 described species, but dozens of undescribed tropical species known in museums.  For instance, anywhere in the tropics, if you look closely at large, broad leaves of Marantaceae or other similar families, you may see something like what I saw in Costa Rica this year:

Stenomicra movie

Notice how the flies walk around the leaf sideways and backwards – but always facing the same way!  This behavior is probably unique to Stenomicra.   The larval biology is unknown for most species of Stenomicra, but specimens in Florida were reared from phytotelmata (water pools formed by plant leaves) in bromeliads (Fish, 1983), a habitat shared with the somewhat related genus Aulacigaster in the neotropics.

A key character diagnosing Stenomicra is the close approximation of the vibrissal setae (two strong bristles just above the mouth, see below); this is more pronounced in the closely related genus Cyamops.  Other diagnostic characters are the forward curving inner vertical bristles (at the top of the head), and the downward bent antennae, with long-plumose aristae (Teskey, 1987).

Head of Stenomicra species, Thailand, showing vibrissal setae.

Head of Stenomicra sp., Thailand, showing vibrissal setae

Taxonomically, the relationship of Stenomicra has been problematic.  It has been placed in several different families, most recently Anthomyzidae, Aulacigastridae, Periscelididae, and even it’s own family, Stenomicridae.  Our recent molecular results (Winkler et al. 2009) suggest it belongs with Aulacigastridae.  One fossil is known, from Dominican amber (Grimaldi & Mathis, 1993).

Finally, for your viewing enjoyment, here’s a few examples of Stenomicra I’ve come across:

Stenomicra spp. from Thailand, Brazil, Costa Rica, and Ecuador

Stenomicra sp., Costa Rica

Stenomicra sp., Australia

References:

Fish, D., 1983. Phytotelmata: Flora and Fauna. In: Frank, J.H., Lounibos, L.P. (Eds.), Phytotelmata: Terrestrial Plants as Hosts for Aquatic Insect Communities. Plexus, Medford, New Jersey, pp. 1–27.

Grimaldi, D.A., Mathis, W.N., 1993. Fossil Periscelididae (Diptera). Proc. Entomol. Soc. Wash. 95, 383–403.

Malloch, J.R. 1927. The species of the genus Stenomicra, Coquillet (Diptera, Acalyptrata). Ann. Mag. Nat. Hist. (9) 20: 23-26, pl. 2.

Papp, L., Merz, B., Földvári, M., 2006. Diptera of Thailand: a summary of the families and genera with references to the species representations. Acta Zool. Acad. Sci. Hung. 52, 97–268.

Sabrosky, C. W. 1965. Asiatic species of the genus Stenomicra (Diptera: Anthomyzidae). Bull. Br. Mus. [Nat. Hist.] Ent. 17: 209-218.

Sabrosky, C. W. 1975. The genus Stenomicra in the Ethiopian Region (Diptera, Aulacigastridae). Ann. Natal Mus. 22: 663-676.

Teskey, H.J. 1987. Aulacigastridae. In J.F. McAlpine et al. (eds.) Manual of Nearctic Diptera, Vol. 2, pp. 891-894. Research Branch, Agriculture Canada Monograph 28.

Winkler, I. S., A. Rung, and S. J. Scheffer. 2009. Hennig’s orphans revisited: Testing morphological hypotheses in the “Opomyzoidea.”  Molecular Phylogenetics and Evolution, 54: 746-762.

News from the Bat Cave! – Monster flies back from the dead!

Friday, December 3rd, 2010

Yesterday we got some exciting news from colleagues at the Smithsonian Natural History Museum in Washington, DC.  Two African dipterists (fly scientists), Robert Copeland and Ashley Kirk-Spriggs,  have re-discovered one of the strangest flies ever found - Mormotomyia hirsuta (literally “terrible, hairy fly”).  We’re looking forward to some more details from them, but in the meantime, here’s a picture of the beast that they emailed out, next to a drawing from the original description in 1936:


Mormotomyia hirsuta, the “terrible hairy fly.”

Drawing from original description.

As you can see, this is a pretty strange fly.  It is large (over 1cm), covered with yellow hairs, and has reduced eyes and non-functional wings (the two narrow straps sticking up from the thorax).  It is only known from a single cave-like rock cleft in Ukazzi Hill, Kenya (map), where it feeds on bat guano. In 1948, V. G. L. van Someren went to the type locality in hopes of finding more specimens and studying the biology.  It’s fascinating to read his account, as published by van Emden in 1950:

The species occurs in a cleft from top to bottom in a large boulder on Ukazzi Hill (Garissa District, Kenya). This cave-like cleft, which isabout a yard wide, with its horizontal and oblique side-cracks is inhabited by unidentified bats. When Dr. van Someren visited the spot, heavy rains had washed down large quantities of bat droppings into the bottom of the “cave” and into a recess in the rock, where they formed a sodden mass. “Literally hundreds of this curious fly swarmed on the walls and around the mass of bat dung; males predominated, but hundreds of females were noted. On the rock margin around the soaking dung were hundreds of pupae, and from some of these flies were actually emerging and crawling up the walls.” Some were seen in copula. Dr. van Someren tried in vain to obtain some of the bats for identification by firing into the cave. Only stones fell and more fies came floating down, the fall of the males being apparently much slowed down by the long hairs, and occurring in a slight spiral line. The lack of prestomal teeth and the large soft labella of the mouthparts (fig. 2) indicate that the adults must feed on readily-available liquid or semi-liquid matter, such as the juices of the excrements and perhaps sweat of the bats. Males allowed to crawl on the back of the hand were seen by Dr. van Someren to apply their mouthparts to the skin and “seemed to be interested only in surface sweat.”

van Someren sent specimens to museums all  over the world, where they have continued to puzzle dipterists ever since.  The species is still placed in its own family (Mormotomyiidae), and we still don’t know what other flies (if any) it is closely related to.  I’m sure more fascinating details of this rediscovery will be coming out soon.

This is a good time to mention another amazing recently re-discovered fly, the European Thyreophora cynophila (family Piophilidae).  This is another large, interesting fly, which feeds on carcasses of large mammals (“preferably odd-toed ungulates”) in advanced decay .  It was described in 1794, but was never collected again after 1850, and had long been presumed extinct.  You can learn about this discovery here:

http://www.youtube.com/watch?v=gwqL02RstAw


The long-lost Thyreophora cynophila, rediscovered in Spain (from Carles-Tolrá et al. 2010).

Thyreophora cynophila, by Jacob Sturm (from Insekten Deutschlands, 1794)

References:

Austen, E.E. 1936. A remarkable semi-apterous fly (Diptera) found in a cave in East Africa, and representing a new family, genus and species. Proc. Zool. Soc. Lond. 1936 : 425-431.

van Emden, F.I. 1950. Mormotomyia hirsuta Austen (Diptera) and its systematic position. Proceedings of the Royal Entomological Society of London. Series B, Taxonomy 19 (7-8): 121-128. (link)

Martin-Vega, D., A. Baz, and V. Michelsen. 2010. Back from the dead: Thyreophora cynophila (Panzer, 1798) (Diptera: Piophilidae) ‘globally extinct’ fugitive in Spain. Systematic Entomology 35: 607-613. (link)

Carles-Tolrá, M, P.C. Rodríguez, and J. Verdú. 2010. Thyreophora cynophila (Panzer, 1794): collected in Spain 160 years after it was thought to be extinct (Diptera: Piophilidae: Thyreophorini). Boletín de la Sociedad Entomológica Aragonesa (S.E.A.) 46:1-7. (link)

UPDATE (12/22/10):

It’s official! Some of you probably saw the news releases on the internet a couple weeks ago, but if you didn’t, here’s a couple links:

http://www.bbc.co.uk/news/science-environment-11948321

http://www.youtube.com/watch?v=7aN4sVWUoLs

http://www.youtube.com/watch?v=dM8HuufOv8I&NR=1

Dance fly website available now at insectmuseum.org

Tuesday, November 23rd, 2010

As I mentioned last month, the Wiegmann lab’s dance fly website has now moved to it’s new home on the museum server. You can find it at danceflies.insectmuseum.org.  Check it out!  You can learn a little about dance flies, their unique mating behavior, morphology, and diversity, and also read a little about our ongoing project.  As a little highlight of what’s there, here’s a few images of some pretty amazing dance flies:

Aplomera sp. from Argentina. Note the eversible sacs on the abdomen filled with eggs.

Hilara mantis, male. Note the mantid-like enlarged forelegs. A very similar species lives in North Carolina.

Rhamphomyia clavator. Note the extremely long, thin aedeagus (male organ). This belongs to a predominantly boreal/alpine species group, all with spectacular male parts.

Allochrotus poecilus. This Andean species is the peacock among dance flies, large and showy. It is the only member of the genus known.

My Favorite Flies: Strongylophthalmyia

Friday, November 5th, 2010

As one of the dipterists downstairs from the museum, I’ve been wanting for a while now to show off some of the more interesting flies. Maybe this will be the first of a series of posts about “My Favorite Flies” (feel free to join in, guys)?

Before I get too scientific, let’s start with a poem:

Ode to Strongylophthalmyia

Stranger beasts there are, it’s true,
Some rare and antiquated.
But I prefer the understated
Strongylophthalmyia.

One fifth an inch from tip to rear,
Much shorter than its name,
So obscure, no praise or fame
Has Strongylophthalmyia.

Awkward, gangly legs persue
A most distinctive head;
The thorax stretched, two long wings spread -
That’s Strongylophthalmyia.

You must admit it’s rather queer,
This creature from the wood,
The rarely seen, misunderstood
Strongylophthalmyia.

I first became acquainted with this family in northeastern Washington State about 7 years ago when I caught a pair of very strange, skinny flies in my net, which turned out to be Strongylophthalmyia angustipennis.  They’ve been sitting in our freezer these past years until I took pictures again recently (below).

Strongylophthalmyia angustipennis, male

Strongylophthalmyia angustipennis, female

This post started a couple weeks ago when I was looking through some malaise trap residues from the Thailand TIGER insect survey, and found three different species of the unusual genus Strongylophthalmyia, one of which had really strange antennae (below). It turns out that several southeast Asian species have projections on the third antennal segment, but this one seems to take the cake!

Weird Strongylophthalmyia from Thailand

Look at those antennae!

Another Thai Strongylophthalmyia

Strongylophthalmyiidae is the longest family name in Diptera, but the flies themselves are pretty obscure – probably few entomologists have collected them. There are now two genera, but 21 of the 22 described species belong in the original genus, Strongylophthalmyia. These flies are generally found on fallen logs, especially of aspen (Populus tremuloides).  The center of diversity appears to be in southeast Asia, where there are undoubtedly undescribed species remaining.  Strongylophthalmyiids are closely related to the equally obscure family Tanypezidae, and may even belong inside this family, according to my friend Owen Lonsdale at the Canadian National Collection of Insects.

If you’d like to read more (and I know you do), here’s some references on Strongylophthalmyia:

Barber, K. N. , Strongylophthalmyia pengellyi n. sp., a second species of Nearctic Strongylophthalmyiidae (Diptera), JESO Volume 137, 2006. pp 81–109.   (online)

Manual of Nearctic Diptera, chapter 59. (online)

Papp, L., Merz, B., & Földvári, M. 2006. Diptera of Thailand. A summary of the families and genera with references to the species representations. Acta Zoologica Academiae Scientiarum Hungaricae 52(2) [pp. 165-172]  (online)

Diptera.info forum with photos here.