Tag Archives: biodiversity

Brazil expedition 5

One of the great things about traveling with other people is that you get to see new ways of doing things. This includes new ways (for me) of collecting flies.

Dalton brought along a Shannon trap, named after the dipterist R.C. Shannon. Dalton’s version is a big, 8′ x 8′, fine mesh box that is open underneath. It is suspended in the air by stakes and string, with just a couple of inches clearance above the ground. Under the trap goes the bait, and this is the mind boggling thing.

Shannon trap


For bait, Dalton used: a whole fish, chicken parts, raw beef, flour, vegetables, fruit, and onions, all heaped together in a one meter square under the center of the trap. The idea is that insects are attracted, and then when they try to escape, they fly upwards and are caught in the trap. The collector could visit the trap, get inside it, and collect what they want.

Well, this trap, after a few days of bait ripening, was a seething mass of flies, moths, and butterflies. It may seem strange, but butterflies and moths are strongly attracted to decaying organic material, just like the flies. One of the most common moths here right now is a beautiful day flying uraniid moth, and we had to fling handfuls of them out of the trap in order to see anything else. Dalton got in and swept around with his net to clean out the flies, but after he was done I was able to photograph some of the leftovers on the reeking pile of decay. Here are a couple of the insects that were attracted.

uraniid moth

happy blow flies on chicken

Mesembrinella

Cyphomyia sp,

Also present, as you might imagine, were fly larvae, or maggots. Some of the attracted beetles were busily gobbling them up, but see what happens to the predatory staphylinid beetle in the video below.

Brazil expedition: day 4

As many of you know, I work on phorid flies, including those known as “ant decapitating flies”, genus Apocephalus. These flies dart down at their hosts, laying an egg in the host body (usually the head). The egg hatches, and the resulting larva feeds inside the ant’s head capsule, consuming about all of the contents of the head. Now, the inside of ants head is not like yours or mine, full of brains; instead, they have huge muscles inside their head capsules to move their massive mandibles (mouthparts). The insect brain is an insignificant little shred of material compared to ours. Anyway, the larva feeds, and eventually the ants head falls off, sometimes before the rest of the body finishes walking around – hence the name “ant decapitating fly.”

There are almost 300 described species of these flies, but we think there are perhaps 200 or 300 more. Therefore, we’re down here collecting, and trying to understand some life history information. We were able to solve one little mystery on this trip.

A couple of years ago, we saw workers of a species of the ant genus Pheidole being attacked by an Apocephalus species, in which the flies seemed to be darting at ant larvae, rather than the adults. We saw the same thing here, and studied it in a little more detail. We even got some video of the flies 

We cut open an old dead log and found a nest of Pheidole. In short order, we had dozens of flies attracted to this exposed colony. We saw the flies darting at the ants when they were carrying larvae, as in our previous observation. We saw, however, that the flies were actually attacking the ants, and not the larvae.

The ants seem to be quite aware of the presence of the flies, and keep their mandibles in the air apparently trying to snap and grab the flies. The ants are highly agile and fast, so this seems to be a formidable defense. Apparently, the flies wait until the ants pick up a larva or pupa before attacking them, as their defense is neutralized when carrying a burden. This seems to me an amazing behavioral adaptation, but it might be commonplace, given our poor understanding of ant/parasitoid interactions.

Brazil expedition: day 3..

Actually we are farther in than 3 days. We are staying in a town called Monte Negro, and have 2 collecting sites: one about 10 km from here, and one about 50 km from here.

On day 3, we went to the 50 km site for the first time. It was seething with insects, from butterflies and uraniid moths to stingless bees and higher flies. We put up 3 of our Townes style Malaise traps, while my colleague, Dalton, and his 2 students put up a huge Gressitt-style, double headed trap. Instantly, this giant black trap became a drawing card for the local insect population. The trap was literally heaving with all the insects inside it and coating the outer surface. Rather than wait for the insects to possibly fly into the collecting bottles, Dalton swept them with an insect net. He made impossibly huge collections of tachinids, syrphids, strats, and myriads of smaller flies.

Dalton sweeping out his trap

I sat down beside the trap, and took a few photos without moving; you can see the diversity of fabulous larger flies here in the following photos.

syrphid fly

for Chris Raper - how is this for tachinid density?

tachinid fly

another tachinid fly

yet another tachinid fly

a final tachinid fly

It is unusual to see such overwhelming diversity, but sometimes it happens. We went back to the same site yesterday and all of our traps were stuffed full to the top, mostly with unwanted Lepidoptera. These we had to laboriously remove from the samples to find the more interesting (to us) material, a process that takes hours upon hours.

As for phorids, we found lots associated with ants, but the best phorid so far was in a Malaise trap sample. The attached photo isn’t the greatest, but it is the best I could do in the field with the fly less than 1 mm long. It is a male Brachycosta, the first I have seen.

tiny male of Brachycosta

Next post: a new discovery in ant decapitating fly behavior.

Brazil expedition: day 2

It is hard to do fieldwork and maintain a blog, especially after a busy day like today. We got up early, went to a café and had horrendous coffee, did some shopping for a few supplies, and then went to the field. A local ambulance driver showed us to a site about 10 km from town. There, we found pretty good 2nd growth forest, and had some good collecting as well. We put up four Malaise traps, crushed various ants to attract parasitoid phorids, chopped open rotten logs to find ant nests, and even saw a fantastic raiding party of Pachycondyla commutata, a ponerine ant that raids in groups and comes back with a huge termite in each worker’s mouth.

These things are what people expect of fieldwork, I imagine. Let’s add a few more details of reality. This is hard work. You are on your feet all day, walking back and forth, carrying water, alcohol, traps, collecting gear, and various other baits and gear. It is extremely hot and humid here, and sweat drips off my face constantly, all day. It takes a couple of days for your body to adapt to such a different temperature and humidity regime, after which you don’t need to regularly drink liters of water, or sweat so prodigiously.

There are mosquitoes and other biting flies here, but they aren’t such an annoyance during the daytime. That role is played by the tiny stingless bees that constantly swarmed around your head, in your ears, in your eyes, and even crawling into your mouth trying to find moisture. It takes a couple of days to learn to ignore them, too.

A day of this type of work lasts until about 3 PM, after which you are usually exhausted, but happy after finding so many cool, new things. But there is work to do: sorting the day’s catch, labeling, and cleaning the samples. This goes on until dinner time (fortunately, we hired a cook, so we don’t have to do our own food preparation), about 6:30 PM, and continues into the night until either the work is done, or you are too burned out to do anymore. Of course, this is the time when you often find something rare or exciting, like we did tonight (but I’ll talk about that tomorrow). Tonight, on our second field day, we stopped working at about 9:30 PM. Cleaning up takes about another half hour.

Neriid fly

Therefore, at 10 o’clock, I finally have time to think about writing the blog. Since we are getting up 6 AM tomorrow to see a new, more distant site from our base, blogging takes the place of sleep. I think I need to bring someone along to do the blogging for me. Any takers?

Weird female Phoridae – Part 3: World’s weirdest fly?

Females of the genus might be the weirdest flies on earth. I don’t say this lightly. Like everyone else, I gazed in open mouth shock at the pictures in Naturewhen it was first described. The fly looks exactly like an ant larva with the head and thorax of a phorid fly glued onto it. And, oh yes, the wings and legs are absent!

female Vestigipoda

Later, researchers published photos of these adult female flies being carried about by their host ants, apparently treated just like the ant larvae. And how did they know they were adult females, you might ask? Well, they published a photo of a slide mount of one of the flies with an egg coming out the end of the reproductive tract.

This is one of the wonders of the natural world, as far as I’m concerned. I have never seen one alive, but my colleagues Henry Disney and Munetoshi Maryama were kind enough to send me some specimens.

The flies are found in nests of the southeast Asian ant genus Aenictus, with specimens from Malaysia and Thailand having been recorded.

Field work

For many of us, going to the field is what we like most about Dipterology (the study of flies). The chance to find new species, experience different environments and cultures, and more than anything, the opportunity to slow down; these are the rewards of the field.

I am on an airplane to Brazil to work with my colleagues Dalton Amorim and his PHD student, Danilo Ament. We have a long-term collaboration based on shared work on phorid phylogeny, thoracic morphology, and tropical inventory. Camaraderie is another pleasant aspect of field work.

This time, we are going to Rondonia, in the southern Amazon. It promises to be a trip of amazing discoveries, as very little collecting has taken place there, other than at Rancho Grande, a formerly popular collecting site that apparently doesn’t have any forest any more. We are going to stay at another area, called Monte Negro, and make excursions from there. Every day (I hope), I will post about our finds, to give the flavor of a tropical Diptera expedition.

For now, I’m just trying to endure the long flights…

A wasp-mimicing flower fly from my last field trip in Costa Rica

Weird female Phoridae – part 2

Another group of phorids with strange females are the Termitoxeniinae. In these flies, the females are found in the nests of fungus-gardening Old World termites. The males and females of at least one African species fly at the same time as their host termites’ swarming, mating and often returning to the same nest.

early stage female

The females then strip off most of their wings, and incredibly, start to grow (few adult holometabolous insects have post-imaginal growth). The head and legs lengthen, and the abdomen becomes grossly swollen, eventually mimicking a termite nymph. The abdomen also has glands that produce secretions that termite lick off. Apparently, they act as appeasement compounds that help integrate the fly into the termite society.

female termitoxeniine

These flies are found in Africa to Southeast Asia. My colleague in England, Dr. Henry Disney, has done most of the modern taxonomy of Termitoxeniinae, including recognizing that the males of the phorid subfamily Alamirinae were the previously “missing” males of the termitoxeniines. These males have little in the way of mouthparts, probably do not feed, and are likely short lived.

male termitoxeniine

What Dipterology needs: a response

Chris Raper (see his blog at http://chrisraper.org.uk/blog/) had a thoughtful reply to my post. With his permission, I’m making it available here as a guest post for flyobsession.

Costa Rican tachinid

Some good points there Brian … how about also:

– We need to work through the millions of indet. and unmounted specimens help in museums around the world. Vast quantities of material exists on our doorsteps but lacks the time and experts to work through them. I know for a fact that the NHM & OUM have a lot of material that has been collected (often in malaise traps) and just sits on the shelves waiting for someone to work on them. The initial sorting can be done by volunteers or students, pinning can be done by out-sourcing but the taxonomic work needs to be done by the very few experts around the world.

– Digitisation of types – we need to make collections more accessible and harness the power of the internet by demanding that all major museums take high-res images of their collections (or types as a minimum) and make these available online free of charge. It might be too much to think that we could see enough to completely describe something (though with deep-focus/stacked imaging this is getting easier) but one of the most basic thing we need to do is to see whether the specimen in our hands looks like reliably-detted material. Just being able to Google for images of different genera would help me immensely and would reduce much of need for loaning valuable specimens or for expensive visits to foreign museums.

– More digitisation of all journals/articles and these to be made available free online. Projects like BHL are doing great work but they are not yet as comprehensive a collection of papers as they need to be. We all still keep far too many paper journals and PDF libraries on our hard-drives – just in case.

– We need to work together – using the internet / modern comms (forums/blogs) to help each other more and to mentor young entomologists and to develop/encourage enthusiastic amateurs (‘citizen scientists’) to pick-up groups and run with them. Online forums like diptera.info and bugguide.net are great for this but I feel that they are under-used or under-appreciated by many professional entomologists who feel that giving IDs to photos or working with amateurs is beneath them or a waste of time. Since setting up the UK Tachinid Recording scheme and providing a strong online presence (as well as seminars and workshops) we have managed to take tachinids from a fringe interest here to something that more and more entomologists are keen to try. We add between 1-2 new species to the British list and most of those from amateurs who have been encouraged by our scheme.

– There needs to be more money to pay for morphological taxonomy. In Europe there are many keen citizen scientists but they have to spend most of their time doing mundane jobs to pay the bills, when their time could better be used doing important taxonomic work. They can only be freed up if they can get contracts or salaried posts, working perhaps at home but attached to major institutions. We have much of the necessary manpower but at the moment it is badly under-funded and under resourced … even simple things like equipment and travel expenses are often down to the person to fund themselves and in hard economic times like these this is getting less and less possible.

I’m sure there are more things but those will do for a start

What Dipterology Needs (in my opinion)

There is a lot of excitement about molecular phylogeny, DNA “barcoding”, whole genome sequencing, and other high-tech advances that will enable us to better understand flies (and other organisms). Doubtlessly, this is where the big money and prestigious Science articles will be concentrated. But for those of us working with whole animals, and not just their DNA, there are a different set of priorities that are no less important. Understanding the world’s Diptera biodiversity at the organism level requires (in my opinion) the following:

Brian Brown collecting in Argentina in 2003

1) More exploration, more collecting. We live in a time of great opportunity. There is easy availability to go to previously remote and inaccessible parts of the world, and to make collections there. On the other hand, other people can get there too, cut the forest, and cause the extinction of thousands of species.

 The tropics, especially, are undercollected and under threat. Huge areas of the world, even if there are well-known for vertebrates and showy butterflies, still have not had their fly faunas extensively sampled.

Collections need to grow if we are going to document life on this planet. Museums need to plan for this type of growth, and curators need to push for it.

I could go on and on about this point, but I think most of you who are reading this are already part of the choir.

2) More study of life history and larvae. The immature stages and way of life of most species of flies are unknown. Terrestrial fly larvae are all but unidentifiable past the family level, and some families do not even have any larvae described. What each fly species does during its larval stage is almost equally poorly known. What are we going to do with all of the phylogenies being generated if we don’t know life history information about our organisms to plug into the framework?

parasitic phorid (Apocephalus ritualis) approaching leaf cutter ant host

3) More study of Baltic amber fossils. Diptera are the most frequent inclusions in 40 million year old Baltic amber. Most paleontologists can only dream about seeing intact specimens of their organisms. We, on the other hand, have the window into the past. I know all groups of flies are not common in amber, but those that are found there need to be integrated with our knowledge of extant flies. There are still huge deposits Baltic amber that have been untouched, and museums have thousands of specimens waiting to be examined by experts in the modern fauna.

Those are my priorities. If you have others, feel free to comment. I have some ideas about how to push these agendas forward, if dipterists can continue to work together.

female Myriophora sp. (Phoridae) on injured millipede

Weird female Phoridae – part 1

female Aenigmatias


In a previous post “What is so great about phorids,” I showed photos of 3 strange looking phorid flies. The first of these is a female that has a body form we call limuloid, after the horseshoe crab Limulus. This is a defensive body form that allows the female fly to live within a nest of ants or termites. The rounded body form, with few large setae, makes it difficult for an ant or termite to grab them (at least, that is the theory!). They used to be all categorized in a group called the Aenigmatiinae, but our knowledge of phorid phylogeny is changing as we know more and more about the groups, so the Aenigmatiinae probably won’t be around as a name much longer.

The name bearing genus for this former group is Aenigmatias, a northern hemisphere genus that includes about a dozen species. The females have a classic limuloid shape, whereas the males are much more normal in appearance and carry the females around in copula. These flies are parasitoids of Formica ant pupae, although no modern work has been done on their natural history.

in copula pair of Aenigmatias

All of the rest of these flies live in termite nests. That makes me skeptical, in part, that they form a natural group with Aenigmatias. Here is the Southeast East Asian genus Epicnemis:

female Epicnemis

The Old World tropical genus Psyllomyia is found in both Africa and Southeast Asia:

female Psyllomyia

The Southeast Asian genus Palpiclavina is less limuloid than some of the others, as it has retained wings and large setae:

female Palpiclavina

But the most limuloid of the phorid females are those of the genus Thaumatoxena, whose abdomens are completely fused into a carapace-like shell:

female Thaumatoxena

Note that the large round things on the head are not eyes; they are antennae. The true eyes are extremely small, and on the very side of the head.