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On 25 June the Museum will open its doors to a special event in celebration of the international and global commitment between countries, industry, charities and academia to work together against Neglected Tropical Diseases (NTDs). This commitment was first agreed upon in London in 2012 and has since been termed the London Declaration On NTDs.
By joining forces to fight NTDs the world would achieve a huge reduction in health inequality paving the way to sustainable improvements in health and development especially amongst the worlds poor. The 25 June sees the launch of the third progress report, 'Country Leadership and Collaboration on Neglected Tropical Diseases'. A pragmatic overview of what has been done, what has worked, what hasn't and what key areas still need to be achieved.
The Museum is thrilled to be participating in this event, having a long-standing history in parasitic and neglected tropical disease research. As both a museum and an institute of research our mission is to answer questions of broad significance to science and society using our unique expertise and collections and to share and communicate our findings to inspire and inform the public. We are excited to be hosting a day of free public events on Neglected Tropical Diseases.
Neglected Tropical Diseases are termed in this way because they infect hundreds of thousands to millions of people, predominantly the world's poorest and most vulnerable communities, and yet receive comparatively little funding for basic, clinical or drug-development research and even less attention from governments, people and the media of affluent countries. Until now!
In total the WHO has identified 17 diseases or groups of diseases that fall within this category.
World Health Organization has identified 17 Neglected Tropical Diseases. 10 of these have been targeted for control and elimination by 2020
The 10 selected by the WHO for control and elimination by 2020 are:
They were selected because the tools to achieve control are already available to us and, for some, elimination should be achievable.
Take the Guinea Worm:
Guinea worm infection - from over 3.5 million people infected in the 80s to less than 130 cases in 2014. Set to be second human disease to be eradicated after smallpox (photo credits David Hamm&Peter Mayer)
In the 1980s over 3.5 million people were infected with Dracunculiasis (i.e. Guinea worm disease), with 21 countries being endemic for the disease. Now, thanks to the global health community efforts and extraordinary support from the Carter Center, only 126 cases were reported in 2014 and only 4 endemic countries remain: Chad, Ethiopia, Mali and South Sudan! If the WHO goal of global eradication of Guinea Worm by 2020 is met then Dracunculiasis is set to become the second human disease in history to be eradicated (the first, and only one, being smallpox). Not bad for an NTD! But there are still challenges!
At the Museum we have a long history of working on health related topics. Indeed our founding father Sir Hans Sloane was a physician who collected and identified plants from all over the world for the purpose of finding health benefits - in fact he developed chocolate milk as a health product.
Today we have a vast and biologically diverse collection of parasites and the insects/crustaceans/snails/arachnids that carry and transmit them. These are used by researchers both in the museum (such as myself and colleagues) but also internationally through collaborative work.
Collaboration is key - Zanzibar Elimination of Schistosomiasis Transmission (ZEST) programme key players: the Zanzibar Ministry of Health, Public Health Laboratories Pemba, the World Health Organization, SCI, SCORE, Swiss TPH, NHM and others
We are immensely proud of our collections and the work we do in this field especially of the biological information we can contribute to health programmes in endemic countries. One of our most exciting contributions is to the Zanzibar Elimination of Schistosomiasis Transmission (ZEST) programme where we are working in collaboration with the Zanzibar Ministry of Health, various NGOs, the World Health Organization and the local communities to identify and implement the best tools and methods to achieve schistosomiasis elimination in Zanzibar. This would be the first time a sub-Saharan African country would achieve schistosomiasis elimination. Fingers-crossed we are up to the challenge! You can read more about this project in an earlier post on our Super-flies and parasites blog
On Thursday we are bringing out our Parasites and Vectors specimens to showcase them to the public galleries and answer any questions relating to these fascinating yet dangerous organisms. Our wonderful scientists and curators will be on hand to talk to people about our collections and research as will collaborating scientists from the London Centre of Neglected Tropical Disease Research who will talk to you about the diseases and the challenges faced to achieve the WHO 2020 goals. Please do pop by and say hello, come and look at our specimens and help us raise awareness of these devastating diseases and the fight to control and eliminate them.
We are working together with schools, communities, government and research institutes to fight Neglected Tropical Diseases. Schistosomiasis fieldwork photo with the team from the National Institute for Medical Research in Tanzania
Posted on behalf of Erica McAlister, Curator of Diptera at the Natural History Museum.
I've just recurated an entire family of flies – and in only three days! It's not often I can do that (I have been recurating the world bee-fly collection for over three years now and it's still ongoing), but then there were only 14 species of this family in the Natural History Museum collection. That doesn't sound like a lot, but after all the shuffling around over the last 40 years with the taxonomy there are only 20 described species within 2 genera.
So in terms of species numbers, it’s a very small family... but in terms of individuals, they are far from small. The family I am talking about are Pantophthalmidae, and they are some of the largest flies on the planet (although I think that Mydidae can rival them). There is no real common name; they are more often than not shortened to Pantophthalmid flies, but are sometimes referred to as timber flies or giant woodflies.
And for such large creatures we know very little about them. This family is considered to be within the infraorder Stratiomyomorpha, but they have not always been positioned here. Originally they were classified within the Tabanidae – the horseflies – and do superficially resemble them (just on steroids) but there are other differences. They were then moved, along with the Xylophagidae, into Xylophagomorpha, but this infraorder is no longer used, with Pantophthalmidae now being subsumed into Stratiomyomorpha leaving Xylophagidae to roam free along the taxonomic highway (Fig.1).
Pantophthalmidae are thought of as being in a relatively stable position snuggled alongside the Stratiomyidae (soldierflies) and Xylomyidae (wood soldierflies). However, I believe some recent work by Keith Bayless of North Carolina State University has now placed the freewheeling Xylophagidae into Tabanomorpha. Everyone up to speed?
Figure 1. Tolweb organisation of Brachycera.
Now we have cleared up the higher taxonomy let's move onto distribution. They have only been found in the Neotropical region from Mexico down through Central America and down through Brazil and Paraguay and across to Venezuela and Columbia. And even though this is a vast area, they are infrequent in most collections.
The key work for this group was undertaken by Val in 1976. He states that these are rare in the collections, but in order to review all of the species and the types, you need to visit 23 different museums (this figure I presume has grown). That is a lot of effort for a handful of species but that would make a great road trip Although our collection goes back hundreds of years we have only 132 pinned specimens but we do have some important type material (Fig. 2). However we are still missing some of the species and one of the genera!
Figure 2. Species in the Museum and whether type material is housed here.
I've always liked this group of flies because they are just so big, and we have actually had some fresh material that comes from some French Guiana material donated to the Museum. It has been sitting there patiently for the last couple of years waiting to be identified and now seemed the ideal time. They had been found by our volunteers, who were surprised by these beasts, as they were so much larger than all the other specimens in the pots.
These flies, as already stated, are big. Pantophthalmus bellardii (bellardi 1862) with its wings spread, can reach 8.5cm in width. Fig.3 gives you an idea of their robust and chunky bodies … we found seven specimens in the donation (of about 50 samples).
Figure 3. One of the glorious specimens - Pantophthalmus bellardii (bellardi 1862).
The adults are sexually dimorphic with the males having holoptic heads (all eyeballs!)
Figure 4. The differences between the males and the female heads of Pantophthalmidae.
And they have beaks! Actually these are a very useful diagnostic feature…
Figure 5. Beaks of the Pantophthalmidae (from Val 1975).
The immature stages are not known from most of the species although we have a range of pinned, dry and spirit material of the larvae. And they too are big, like their mothers and fathers, but we have even fewer of them in the collection (Figure 6 & 7).
Figure 6. Pantophthalmid larvae in relation to adult (abdomen shown).
Figure 7. The Museum spirit collection of Pantophthalmidae.
Why do we only have one jar? One of the problems is that the larvae are wood borers and inhabit galleries that are carved horizontally into the tree – dead or living depending upon the species. We still really don’t know what they are feeding on but many people believe that it could be fermenting sap. Others believe that the diet is a mixture of wood (either dead or in the process of dying) and micro-organisms.
Zumbado writes in his work from 2006 that they seem to prefer mucilaginous trees such as kapok or sap-producing trees such as figs. He goes on to describe how noisy these little critters are – several hundred may be in one trunk and they can be heard munching away from several metres.
The larvae have very robust head capsules and massive mandibles – they are some of the largest larvae I have seen (of all insects). When I read accounts of how many can be seen in one tree, I am quite overcome with envy. We don’t have many in the collection – one jar as shown – but it is a mighty jar. I don’t think I am allowed to say what exactly was said by various colleagues when we brought out some of the specimens but, suffice to say, they were impressed.
This collection was in a sorry state in old drawers and on slats. These are problematic because the pins are so firmly wedged that when you try and remove the pin from the board you often damage the specimens. The specimens themselves were showing some early signs of damage with verdigris on some of the pins (Fig. 8) Verdigris is when the lipids in the insect react with the copper in the pins. Nowadays we use stainless steel pins, so this doesn't happen, but most of the specimens in the collection are mostly older even than me.
Figure 8. Verdigris on pins.
The first thing that I do when I recurate a collection is to find all of the recent as well as the historical literature in catalogues and monographs, and update the database. The Museum database for this family had not been edited for at least 20 years. But luckily, when going through the literature, I discovered that with this family, not a lot had happened in that time. But our records were still inaccurate, and for a family with very few species people kept changing their mind about the number of genera and where the different species sat. Sorting that out took the most time in terms of overall curation, as there were so many new combinations and I had to be certain of all the taxonomic rearrangements. You should have heard my sighing as I was typing in the data (I promise it was just sighing).
Remember that there were only 20 described species of which we had (past tense is important here and I’ll come back to that) only 15? Well, the number of taxonomic records we now have in the database of all the original combinations and numerous synonyms (the many, many synonyms) is about three times as many as the actual number of species (Fig. 9).
Figure 9. Taxonomic names for genera and species.
Once this was sorted out, I started on the production of the labels. I have to produce an initial first draft of the list of species names (Fig. 10) as I need to ascertain where and what all of the types were, as well as how many unit trays of each size are needed. I have many lists scattered around my desk so one more can’t hurt…
Figure 10. Lovely lists of the species of Pantophthalmidae in the Natural History Museum Collection.
N.B. See – hardly any valid species names without synonyms!
Next I needed to make my unit trays up. My lists have codes on them indicating what the type was and how many of which size trays – there is an awful lot of organising with curation and it definitely fulfils my OCD tendencies…We have three sizes of unit trays that we use for Diptera recuration but somehow I knew that I probably wouldn’t be needing any of the very small A trays (Figure 11).
Figure 11. Unit trays –C, B and A.
N.B ok that is quite a nerdy photograph!
The new sparkly labels (ok the sparkly bit is a lie) were placed into the unit trays and then I started transferring the material across. As the specimens were moved they were inspected for damage – any verdigris removed and any legs etc. placed into gelatine capsules. Three new main drawers later and the collection was now housed in museum-standard drawers, conservation-grade trays and labels, completely updated on the database and new material incorporated into it (Fig. 12).
Figure 12. The largest smallest recuration project.
So let’s go back to this new material consisting of just a few specimens. Not a lot you may think – but remember this collection is not very big. For large flies, they were slightly difficult to ID. In fact, as the samples had come out of the window traps (the specimens collect in alcohol) they were very greasy.
Chris Raper, a fellow Dipterist at the Museum and lover of these flies, suggested that I give them a bath in ethyl acetate. I was a little nervous about leaving these precise specimens overnight in this rather noxious fluid. But lo and behold! What wonders were to great me the next day! Wonderful, they were – just wonderful. And suddenly we were able to see features that were previously hidden, such as thoracic patterns and, rather more importantly, hairs on the eyeballs. This feature alone split the two different genera and so we realised that for the first time, our collection now has ONE Opetiops alienus (Fig. 13). I believe this is also the first time that it has been collected from French Guiana.
Figure 13. Opetiops alienus – check out not only the hairy eyeballs but also the beak!
So one database updated, one collection rehoused and once more new material has been added to the collection. Happiness reigns in the Land of the Curator.
OK, I have decided to create #Worldrobberflyday. All the time now, we hear that this large mammal or that large mammal has a 'day', and that got me thinking. Buglife have an invertebrate of the month, but even they are not very often the lesser-known insects, including the flies.
And I wanted global. Let the world celebrate! Why is it always the large stuff or the pretty (and, in my opinion, slightly less important) species? So I thought about it and decided it was about time that we championed more aggressively the rights of the small and endangered flies. These creatures are some of the most charismatic animals on the planet. The robberflies, or Asilidae, are truly worth celebrating for their looks, for their behaviour, for their good deeds to us, and because many of them are threatened.
The UK boasts 28 species of Asilidae (OK, so that's not a lot in terms of flies, but hold on – we have only 30 native terrestrial mammals, of which 17 are bats and 2 are native marine mammals). Globally there are more than 7,500 species, and as such, it is one of the largest families of insects today. In fact Torsten Dikow, a world expert on this group, has them as the third most speciose group of diptera. This is a group, therefore, that has a large impact on the environment in which they live.
Asilidae are Brachycerans (Fig. 1), which are the more advanced and robust flies. Asilidae are known from the Jurassic era, but some of the more important finds are from the Cretaceous, including those from the Crato Formation of north-eastern Brazil (approximately 112 million years old). This site is truly extraordinary in terms of the invertebrate remains that were found there (and just another reason for me to get back to Brazil!).
Figure 1. Phylogenetic arrangement of Diptera showing the more advanced Brachycerans and the position of the Asilidae (robberflies) within it.
It was again Linnaeus, or Linne, who described these flies in his 10th edition (1758) Systema Naturae when he erected the genus Asilus. Within this, eleven species were described and then a further four were added in the 12th edition. You may be unsurprised to know that most of these are no longer in the original genus! Ten have been moved to other genera, three we are unsure of due to the original descriptions being vague, so that leaves only two in the genus.
However, the species Asilus crabroniformis, commonly called the hornet robberfly in the UK – and the type species of the family – still sits within this genus in all its magnificence. The division of flies into different families came later with Latreille, a very eminent entomologist who tried to put some more organisation into the entomological hierarchy in 1802. Since then we have increased the number of species and have split the family into many subfamilies –14 in fact (Fig. 2) But as regular readers know, Dipteran taxonomists are still not satisfied and expect more movement in the future.
Figure 2. Subfamilies within Asilidae (image is Tigonomiminae © Thomas Shahan).
Even still, you can comprehend how much work has gone on into understanding the relationships within this family so far.
So why are people interested in these flies? Well once more, this is a family of flies that rock! And these rock harder than most. All armed with moustaches and powerful piercing mouthparts, these predators are aptly named, as they truly are the most vicious and effective aerial predators. These flies are venomous, probably both as adults and as larvae (although we know so very little about the offspring). The adults are able to catch, then sedate, their prey whilst on the wing, suck out the contents and then drop the husk of what was once a living breathing entity. It's almost poetry.
And to be fair, to catch these little predators you often have to become a predator yourself. There is no majestic leaping around the countryside, freely swinging your nets with wild exuberance: instead you must 'become the fly'. You stalk it; determine where it rests and then strike. If you are me, this is often followed by a squeal of delight or a wail of despair. I once spent a glorious afternoon on one of the Isles of Scilly at the beach (obviously working very hard) trying to stalk these flies. My volunteer and I tried to work in unison hunting them, and I could almost hear the flies mocking us…
The adults are most active during sunny, hot conditions. Again, another reason for loving flies – they have an affinity for the nicer weather conditions.
Although these flies range a lot in size, from 2mm to 6cm, they all share distinctive features that help identify the family. The adults have enormous eyes, which is one of the many tools that make them such efficient predators. And it also helps us recognise this family easily. The bulbous eyes and the distinct dip between the two eyes are very characteristic (see Fig. 3). They can swivel their heads around and their eyes can see what's going on behind them as well.
Figure 3. My, my... what big eyes you have...!
Some of them scout amongst the grasses, their rapid wingbeat enabling them to turn whilst hovering. These truly are the stealth-bombers of the insect world.
The leptogastriniiae are the skinniest of the Asilidae, with very long bodies and legs. They use these long, gangly first two pairs of legs to catch their prey whilst – we think – using the third pair to stabilise themselves. Not all actively scan like this: some will sit and wait, only darting out to impale their prey when they are ready. If fact, there are several different ways in which they hunt and, as with all good scientists, someone has devised a terminology for all of these (Fig. 4)
Figure 4. Lehr (1979) from the Geller-Grimm Asilidae site.
For that is another characteristic of this group – a well-formed, stout beak often hidden in a luxurious moustache or, more correctly termed, a mystax (Fig. 5).
Figure 5. Mouthparts of a robber fly (Brachycera: Asilidae). an=antenna; cl=clypeus; ip=hypopharynx; li=labium; ls=labrum (epipharynx); m=mystax; ms=maxillae; oc=eye; pm=maxillary palpus © Giancarlo Dessì. Licensed under CC BY NC SA 3.0 US.
It is the needle-like hypopharynx (Fig. 5) that pierces their prey. This is not for the faint-hearted, as they often try and pierce the soft parts of the insect, such as the neck or sometimes the eyes. They have this moustache (Mystax – Fig. 5) to help protect their mouthparts from the flailing prey.
They don't have to flail for long, though, as the fly injects saliva that contains nerve toxins that paralyse the prey, and proteolytic enzymes that dissolve the insides. They are nasty for insects, spiders, and occasionally a very unfortunate hummingbird, but apart from giving a nasty jab, they are not dangerous to humans. Research done by Adamovic in 1963 found that injecting robberfly saliva into invertebrates kills them instantly, but they never inject venom into humans. There are several researchers in the Natural History Museum who are now studying the venoms within these flies, so watch out for future Museum publications to follow what is happening in this field.
But this leads me to one of the first reasons that these flies are very important. It's because they are such good predators. Within the UK, between 1930 and 1933, Hobby produced a list of the prey records (Fig. 6).
Figure 6. Hobbies lists from Stubbs and Drake 2014.
We have spent the last century working out the prey species and now have a greater understanding of the potential impact these flies can have in helping control populations of species that we often consider as pests – with aphids being a classic example. Although they are opportunistic species, they can have an impact on the overall densities and therefore become the gardener's friends.
So let's move on to courtship. As with most creatures, some do, some don't; with some species the males just grab, while others put a fair amount of time and effort into it and have different modifications on their bodies to both attract the opposite sex as well as hold on to them. And it's not just the males that do the flirting. Oh no - there are some females that entice the male.
The rather unusual courtship of the British robberfly Choerages marginatus was described by Ian Rabarts in 2009 (paraphrased from Alan Stubbs' rather amusing synopsis on the subject, in his and Martin Drake's book British Soldierflies and their Allies): Firstly the flies recognise that (a) they are the right species, and (b) that they are of the opposite sex (a very good start in most situations to do with copulation leading to fertilisation).
Then they check out each other's hunting moves and, if OK, the female stands facing the male in a sort of 'yeah, you'll do' posture. After this, she flies in a slow 'flaunting' circuit (hussy) very similar to that of a prey item (all very kinky). He attacks when he sees her 'shimmer-strip', whereupon she slows down her flight, but flies in an angular pattern. He realises then that this is his lady and adjusts his attack from one of capturing prey to one of copulation.
Alan then states in his book: 'Failure [of copulation] results in going back a few steps in the courtship sequence.' A not-unfamiliar event…
Bob Lavigne, a collaborator of mine and another international robberfly expert, wrote in 2003: 'It is postulated that courtship first developed when male search flights (which end abruptly with copulation), were consistently unsuccessful.' It sounds so final when it ends with copulation!
In fact, reading the literature when it comes to robberfly mating in copulation has been very entertaining. Morgan (1995) records that another species that were just about to do the do were scared off by a sheep! Given the size difference I too in a similar position may have been scared off...
But check out Pegesimallus teratodes (Fig.7) – these have amazing structures on their hind legs. These are used in the dance of the males to attract the females –they are indeed the peacocks of the robberfly world.
Figure 7. Pegesimallus teratodes and its amazing legs.
And that is not all that is fantastic about the males. I would be remiss if I didn't mention the genitalia of the males (Fig. 8).
Figure 8. The male Pegesimallus teratodes with his rather impressive genitalia.
And then there are specimens in our collection that we think give us an indication of a courtship story, although I doubt we will ever be able to find out for certain. Take, for example, two specimens of Mallophora infernalis from our collection (Fig. 9). Now, had the female caught the bush cricket and the male had thought:“Excellent! Both food and sex!”? Or, had the male caught the cricket to attract the female? Either way, it was not going to end well for the bush cricket (or in this case for the robberflies).
Figure 9. Male and Female of Mallophora infernalis who were caught mid air carrying this bush cricket.
So whether there is dancing, waving, differences in wingbeats, or offerings, the end result hopefully is the production of eggs. And blimey, the females have a big range of ovipositors (egg laying tubes) (Fig. 10)!
Figure 10. Ovipositors (adapted from Stubbs and Drake 2014).
Now this is where it gets tricky, as we know less about the egg and larval stage than any of the others. And this is the main reason why we should be concerned about these gorgeous creatures – many of the UK species are rare. We have no real idea for many species globally but can only assume that this is the case everywhere. In fact, several of our UK species are protected.
However we don't know much, if anything, about many of the species' diet, where they live, development and so on. In Collins' book The Conservation of Insects and their Habitats, he discusses how little is known about the species, despite the fact that they are classed as threatened.
Take one of the most charismatic insects in the UK (no bias there) the hornet robberfly Asilus Crabroniformis – a mimic of (you guessed it) a hornet. There is still very little information. Previous work dating back to the 90s states that the eggs were laid in or under the old dung of cows, horses and rabbits, and soil nearby. Maybe the adults (and subsequent larvae) are that flexible in their habitat? The larvae are then thought to feed on dung beetles but again this has only been observed (and not by many authors) during late-stage instars. What do the little ones eat? It is a UK priority species and we need to know more about it. How can we consider conserving a species (if it needs it) if we don't know where it is or what it's getting up to? It's like a wayward teenager.
Now, if you want to know more about what is going on with UK robberflies, there are loads of pages giving you what information there is.
Figure 11. Nature spot.
But what we really want now is information coming the other way. Personal observations in the field, the location of eggs and the like, and species distributions are all critical in ensuring that we maintain and enhance our existing populations.
Martin Harvey @kitenet runs the UK recording scheme for these wonderful little animals (See Fig. 12 or visit the website) and you can send all your records to that site. Martin also runs many courses on these as do others in the Dipterists Forum, so sign up and go along to them.
Figure 12. The Soldierfly and allies recording scheme, which includes the robberflies.
So there you go - robberflies are amazing, and they do need celebrating. And if you still need convincing here is a little fluffy one to tug at your heartstrings. When asked what is my favourite fly, Laphria flava is at the center of my heart (Fig. 13).
Figure 13. Laphria flava male.