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 10^th 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 12^th 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.

Moustaches and mouthparts

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.

Flirty flies

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.

There is a nice little piece by naturespot (Fig. 11) featuring some of the UK species, and of course you must check out the Dipterists Forum for all of their information.

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.

It's been a while but we have now the penultimate installment of the Peruvian Adventure by Dave the driver Hall...enjoy.

I think that fourth night must have been the first one I've spent at 2,700m and I didn't seem any the worse for it. I tugged at the wooden shutters to see what day five on the road might have in store. Weather: acceptable for driving on dodgy roads. High, thin clouds cut with watery pastels. A shabby old town in diluted blue and sunbleached turquoise. The plaza mayor was just creaking into life. A cluster of women in straw hats held conference outside a grocer's. A policeman heaved open the giant wooden double doors of an eroded old police station, yawned, and spat.

I took a cold shower, dressed and started lugging trunks and sample boxes from last night's sorting. Prof. Knapp was already up (of course) dismantling the drier. The daily task of packing seemed a little more arduous this morning. Either the altitude, or the shin-barkingly steep antique stairs. The van was parked in a square pound at the back of the hotel, which looked appealingly like the OK Corral. Sandy had been a little concerned that the truck might not still be there this morning, but the locals seemed harmless enough to me, if not exactly chummy.

The growing light revealed our hotel to be of a certain vintage; much of the rear was semi-derelict and empty. I creaked back and forth with my boxes through creepy cavernous dusty backrooms, using the return trips to investigate dark passages and musty staircases leading nowhere, the only sounds my wheezing and the drip of an old tap. And here an appealingly dilapidated old dining room-dance hall I could imagine thronging with local revellers.

Morning in Celendin.

After breakfast I took a few moments to explore the town, too. It might be old hat for the Dr Livingstones in our midst but I was unlikely to set eyes on the place again. Erica likes telling me how amusing it is reading my rhapsodic perspective on what she sees as routine grubby fieldwork: I see cascades of mountains; she sees dirty socks drying on the dashboard.

(Erica here - not exactly how I phrased it - he was bemoaning us for failing to see the beauty all around us - Sandy and I were concentrating on flies and spuds )

The market was already open for a day's easygoing trade. I ambled over. Three schoolboys kicked a burst ball to each other on the way to classes. The policeman hadn't moved. Stallholders unhurriedly erected awnings and set out their wares along the narrow thoroughfares, the alley-tunnels filled with the pungent aroma of meat, overripe fruit and hawker-stall breakfasts. I bought plump oranges and tomatoes for lunch from one of the impassively leather-faced vendors and wandered back to the hotel, ready for another day behind the wheel.

But no! Erica announced she'd be driving today, to 'give me a break'. The cheek. I protested firmly, in my quietest voice. This felt like cheating, but I was anticipating incredible scenery, ahead so I didn't flap.

(Erica again - they are long days driving- even we are not that nasty to make him drive continuously)

In contrast to other towns thus far it was a fair doddle finding the route out of town. Without at least two simultaneous sets of directions being offered in each ear, the going seemed somehow easier. Being fair, it wasn't hard to navigate. There was little traffic, and thanks to the colonial grid system we simply had to find the edge of the town and keep going until we hit a road going east.

Nevertheless, this road looked unpromising – a narrow back-street cluttered with the detritus of townsfolk's lives: bits of motorbike, smashed agricultural implements, underfed dogs...

But here a sign, which told us it was a mere 150km to our next stop, Leymebamba, and presently we started climbing.

The narrow road wound up again through foothills scarred with gold-mining quarries, many illegal. The locals had been protesting for some time, largely to deaf ears, that these mines – many sponsored by American multinationals – are polluting the water supply.

Above the scarred hillsides we rose... the road surface was perfect and I couldn't help thinking what an epic bike ride this would make for the stout of heart. Eventually the treeline gave way to rousing views of Celendin far below, where the light-blue double steeple of the church in the town square poked above the ramshackle rooftops. The town nestled in a half-bowl surrounded by hills. It must have looked attractive to the early Inca settlers and, unfortunately for them, the Spanish too. The head of the valley ended in an unseen drop, and far beyond were mountains whose peaks seemed oddly level with the town itself... now it was clear how high up the town was.

Still we climbed, this time without finding any locals to pester about their potatoes. Spying as yet no specimens, we meandered upward and upward, through rugged moorland, ever closer to the clouds that before had seemed so far off. As the sun finally renewed hostilities and the clouds began to leak a bit of sunshine, we reached a high pass of about 3,500m where a tiny village sat incongruously amid the rugged landscape, complete with a tiny football pitch and neatly planted conifers. The place had a strangely manicured feel.

Then, suddenly, the other side. As we breached the other side of the pass, a completely different panorama opened up. A dramatic series of valleys and mountain ranges rolled into the east, rib upon rib wreathed in mist, multiple horizons fading toward the Amazon. Somewhere to our right, far below and well beyond view, the Marañón River was thundering on its 1,700km looping journey toward the king of rivers. My head span at the spectacle. Sandy and Evelyn discussed tomatoes. Erica drove on without comment.

Our way wasn't getting any wider. As we wound downwards, hugging the cliffsides, the road only narrowed further. The bends were like fishhooks, and here and there were patches where the roadworks had not reached or where recent repairs had simply slid down the cliff. There were no barriers to protect motorists from the yawning 1,000-foot drops a matter of inches from the wheels. Superfluous roadsigns warned us to slow down and keep right. Erica didn't need much encouragement. Everyone in the car seemed to become silent. I tried to look far ahead to see if anything was coming the other way. We could only imagine what it must be like for lorry and bus drivers.

I was beginning to enjoy myself.

A yawning 1,000-foot drop inches to the left.

In the clouds now. I like being in clouds, but it doesn't help with the driving. Breaks in the mist revealed teasing glimpses of dark, sheer mountainsides. Here and there the sun poked through and a rainbow made a perfect technicolor arch over the road.

Driving through the Peruvian mountains.

Then just as suddenly, out of the mist, full sunshine, the scenery changing from hairpin to hairpin. We were descending toward a lush shoulder of high land, an upper valley nestled in a crown of mountains far below, dotted with tiny farmhouses and quiltwork cornfields, into which the road descended in a series of insane switchbacks. It was a perfect lost valley; a prime spot for Eldorado.

A prime spot for Eldorado.

I still have no idea how Sandy spots specimens from the car even at the modest speeds we were achieving. But at last Prof Knapp bade us stop for our first samples amid a gradually drier landscape.

The sun was melting the clouds away and the morning was mellowing nicely. Nearby, an allotment of sorts, a small bungalow and what I thought were petrol pumps. The immediate area was lush, catching runoff rainwater in a small series of irrigation ditches. Prime mozzie territory, I thought. Again, parts of the area had been cleared recently – the solanum species again proving keener than mustard to move in quick on new space.

My ridiculous sample notes about the sampling area – for 'twas my job – read: “A small irrigation ditch is nearby and a 'petrol station' nearby also.”  I see now it was not a petrol station, but someone's dwelling, but their toilets seemed public enough at the time.

Sandy and the Fly Girls exited, rummaged in the back for Sucky and Sweep, then set off into the undergrowth. Evelyn swished gamely. Erica bothered a bush. I made notes. Sandy snagged some excellent samples of Solanum dilleni. I went to the toilet again.

(Erica once more - many conversations on fieldtrips revolve around toilets - how often you need to go, the facilities etc)

On we went. As we sank riverwards, hopes rose in the back of the truck that the ever-more arid terrain may harbour the tomato relatives we had encountered in similar habitats earlier in the trip: habrochaites perhaps. It was getting drier and drier. I prefer the lush stuff up in the mountains.

We fairly freewheeled to the next stop a couple of miles hence, where a sharp bend in the road concealed a small clutch of solenum arcanum known from Sandy's notes to be in this location many years previously. It was still there. All manner of insects waited to be sucked from the bushes, but nearby sat a sizeable troop of Homosapiens Peruensis, taking a break from mending the road. They were much animated by the sight of Erica's immense suction apparatus. We had disturbed the species in its natural habitat, so had to bear with good grace the sniggering and what I imagined to be Spanish double entendres. The Challenges of Fieldwork.

My notes say we came away with some samples of “Solanum simplefolium” but, according to Google, this doesn't exist. That's a shame – I liked that name. I can only imagine it was Solanum pimpenellifolium. This sports little purple flowers and tiny tomatoes – tomatillos – which are edible. It's a really close relative of our tomatoes. Indeed, it is sometimes called a wild tomato.

Some Peruvian geology.

Further we sank toward the Marañón in our search for tomato and potato data, through spectacular peaks and pyramids of twisted volcanic rock where lava seams poked through like ribcages, past abandoned pasture and the occasional hungry-looking donkey picking through the brush.

At last we reached the valley floor, at the village of Chacanto in the district of Las Balsas – gateway to the Amazonas region. It was now all firmly semi-desert, reminiscent of parts of Nevada or Utah, catching the full ferocity of the sun. It felt like being stir-fried. The river looked inviting, but the Marañón slides through at a good clip here even in the dry season. It is a mere stream compared with what it would become downstream, but the bridge that spans it is a good 100m in length. We rolled over the bridge, stopped only a few minutes for a coffee in the sleepy village, and went on our way. We still had a long way to go...

The Marañón River at the bottom of the valley.

Erica - since writing these blog pieces we have been analysing some of the data and trying to figure out what some of the insects that we sampled are. It has taken months to do this and there have been at least 9 people so far going through the insects. many are about to be sent of to specialists across the globe. Upstairs from where I am typing this at my desk we have two people imaging some of the specimens before they are sequenced for their DNA....its a very exciting time for this project.

I have been away alot recently (that sounds familiar to all that know me) and one of those trips was a field trip to Peru. In fact I brought my partner with me to be our driver and field assistant. This is a big gamble - would we be able to cope without killing each other; would he understand and enjoy what we were doing; would he drive us off the cliff? These were all considerations that we pondered but eventually decided that it would be great - if we couldn't explain to him the value of our work then we reallly needed to work on our communication skills.

However it wasn't a holiday for him - as well as the driving we made him press plants, collect insects, take DNA samples, transcribe field data and also I made him write my blog . There was a lot so he will be doing it in instalments as he also has a day job . It has been enlightening reading it and seeing what we do through the eyes of another.

Without much further ado, I give you Dave:

For reasons best known to herself, The Doc thought it would be a good idea for me to come with her to Peru for two weeks as her field assistant/driver/Odd Job man. Part of the deal was to see if I could write her blog for a few days. Folly! The idea is that I might provide an outsider's perspective on what Erica does, as prior to this I had little experience with fieldwork beyond high-school geography. So I gave up two precious weeks of holiday and relented.

I've never been to South America. It's not something you pass up. I paid the air fare, but much of the (admittedly inexpensive) rest came free. As an editor in my job, at the very least this would be an opportunity for me to ask some awkward questions! So I'll be filling in for Erica and revealing what she and Dr Sandy Knapp, botanist extraordinaire and leader of this expedition, find in Darkest Peru (© Paddington Bear).

The gang.

It took 20 hours of flying and 14 hours (más o menos) of driving to get our first sample, so let it be known that the Museum goes far for our money. We were joined by two wonderful spirits of the insect and plant world: Evelyn Gamboa of the entomology dept of the University of San Marcos in Lima (the oldest in the Americas) and later by botanist Segundo Leiva Gonzales, Director of the herbarium at Antenoar Orrego University in Trujillo.

First question: what are we doing here? Is it worth it? Is this some sort of jolly? I'd suspected Erica led a charmed life coming on these trips, which she called work. But I had to keep an open mind. So of course we're here to collect plant and insect samples. Specifically it's plants of the Solenacaea family (i.e. nightshades - wild relatives of our cultivated tomatoes, aubergines, potatoes and tobacco) - and the pollinators, pests and associated microfauna thereof. In particular, we'll be collecting diptera - true flies, which you'll all by now know about already if you follow Erica's blog.

Sandy says this is the first study we know of that samples both the plant and associated insect population together, in situ. The success of this trip - or otherwise - could have extensive repercussions for future study. Naturally, this trip will also add to the Museum's (and by extension, the world's) knowledge of these species, and will boost Segundo's university's collection. We'll also be able to tell what's happening to the distribution, prevalence and range of these species over time (many records go back decades).

And the data they find here could have a wide variety of applications. For example, a changing climate might put stress on current cultivars of tomatoes. Crossing these staples with certain varieties of their hardier Peruvian cousins might increase pest resistance, or tolerance to drier conditions for instance - agricultural benefits with with knock-on effects for food security, natural pest control, biodiversity and species distribution.

But, before all that can happen, we had to find them first. That meant a day of driving up the Panamericana north from Lima. We had the right car for it - a 4x4 Toyota the crew likes to call Freddie. It is owned by a man called Martin, who has never learned to drive it. I will be happy to test-drive it on this occasion. I will not be calling it Freddie...

Dave and Freddy.

Away from the sprawl of the capital

Once Freddie had escaped the sprawl and grubby winter permafog of the capital, we hugged the coast up the Panamericana and the fog lifted. The scenery slowly evolved from apocalyptic ashen desert into drifting caramel dunes, lonely pastel mountainscapes and roads that vanish on the horizon. We stopped in a roadside café made of reeds with a toilet located tellingly far from the main building that had no water, no toilet paper - but did have a colourful penguin collage painted optimistically on the outside. Yet here they served us the freshest and tastiest ceviche - perfect fodder when the thermometer is climbing above 30degC.

We spent that evening in Trujillo, where the crumbling colonial mansions and old courtyards of the old town seemed to me to be a vast improvement on what I'd seen of Lima at that point (which to be fair, was not much). Yet I felt I had been in the country for some time - a result of that temporal illusion you get when you're a bit jetlagged and you've crammed so much into a short period. But as Erica and I shared a beer at the end of a dusty day, I realised we hadn't even taken our first sample.

At 6.30 the next day we were off. We headed north again on the Panamericana and after an hour or two, turned right towards the distant mountains, roughly following the river Chicama. After a brief stop for grub in a charming market village called Roma we wound our way up a dry valley interspersed with fertile arable land into the foothills of the Andes. The dunes had given way to scrub - semi desert - where stately cacti pointed skyward and the road deteriorated into a dirt track full of entertaining potholes (n.b. not entertaining for everyone in the car). We stopped occasionally to sample the plants, and Erica showed Evelyn the ropes of how to collect with nets and Erica's primary weapon - the suction sampler. Basically this is a handheld vacuum cleaner with a net and container for catching the insects. Anyone wielding it looks like That Fourth Bloke in Ghostbusters. It looks daft, but it does its job. Vultures hovered hopefully in the blue as we inched inadvisably on.

The variety of landscapes.

Hours of lurching later, Sandy bade us stop at a loop in the road, an unconvincing turnoff to a place called Colbot, having seen a likely candidate. Her instincts were correct - a single specimen of Solanum habrochaites clung defiantly to a cleft in the bend. This is a wild tomato species that is found on the western slopes of the Andes from central Ecuador to central Peru. This species is notable partly because, with a bit of crafty crossbreeding, it yields 20 times more sugar than the cultivated tomato - a matter of keen interest to the Heinz family.

Erica and Evelyn got out and swept their nets gamely - Erica performing a more detailed local sample and, as had been decided, Evelyn with a more free role, performing a general sweep in all the sites we encountered. Sandy cropped herself a small sample when they'd finished swishing. Here Erica discovered a beefly among the other unfortunate captives in her killing jar. As we know, Erica gets soppy about beeflies. But not so soppy as to let them go.

Segundo took a sample of Capparis scabrida - a relative of the caper plant - sprouting in the dry riverbed. Then Erica and Evelyn swept the hell out of this area with their nets and Erica seemed interested to have caught a micropezidae - stalky, stick-legged flies, which she feels are "quite funky".

We stopped for lunch here. A local cowherd came and joined us and he told us that there hadn't been any rain that year, and that it was making life difficult. I can but try and imagine. I was finding it hard to believe we would find much in this environment. But not for the first time I would be proven wrong.

Life finds a way

A single mototaxi - a tuktuk - wobbled past us carting an old lady, probably from the market in Roma. We'd passed it several times and when we'd stopped to look for specimens and it had crawled past us, the tortoise to our hare.

The 'tortoise' to our hare

The vegetation became more abundant, as the road gathered height, along with my spirits. Not that I wasn't fascinated with the desert but, given a choice, I much prefer the mountains and greenery to deserts, and the scenery was becoming more and more preferable.

Several stops and samples later, we made a final stop in a bend where a stream passed under the road a mile on from a charming mountain village called San Benito. This location was teeming with life. Humans included. Children from the nearby village came to say hello, all curious to see what these gringos were doing on their patch. All except one young lad, who was having a bad day and preferred to throw stones at his friends. For this, his big brother took him home upside down.

Where there's water

Meanwhile, we swept for various insects, and I carried on my supplementary job of detailing the GPS location, weather conditions and general description of the sample site. I was also given the seed-collecting detail. Lots was found here.

Sandy found three different kinds of wild tomato and then casually announced she had discovered  a new species of Browalia - a Solanacaea species sometimes grown ornamentally like petunias. This was something I found astonishing but to the experienced botanist, it was merely very interesting. And Erica discovered a few snail-killing Scyomyzids -the presence of moist liking flies was presumably testament to the damper conditions.

After an hour or so of sweeping, the mototaxi pottered round the corner, passed us again and disappeared round the corner for the last time. 

Colourful buildings of San Benito.

After a welcome supper in a very rustic kitchen in San Benito, where Segundo secured us berths in a municipal hotel, Erica and Evelyn started pinning the specimens, Sandy set up her plant-dryer - an insulated stack of card and wood heated overnight by a small gas flame - and I started logging the samples we had found on Erica's ancient laptop. By the time we had finished it was time for bed.

But first I felt I should at least reacquaint myself with the night skies of the southern hemisphere and say hello to the Southern Cross. I avoid the overused word 'awesome' if I can, but it seems perfectly fitting here. I've never seen the stars quite as clear as that night in San Benito. I thought I had made some sort of mistake - but no, it wasn't low cloud, but the distinct ghostly veil of the Milky Way. '

To be continued....

So that was Dave's first thoughts on fieldwork with us..More blog pieces to follow....

This blog piece is written by the young and keen Victoria Burton, who rashly agreed to come away with the Museum's team of dipterists and the Dipterists Forum to Speyside in Scotland....here is her story.

Hello, I’m Victoria and I have just finished an MSc in Taxonomy and Biodiversity,  run here at the Natural History Museum, London.

I am also a fly fan, so when Erica mentioned there may be a space on the Museum’s collection trip to Scotland with the Dipterists Forum I had to tag along! As a born and bred Southron this was my first trip over the border and a great opportunity to see some of the habitats and species which are not found ‘down south’.

The trip started on a Saturday in September with an early meet up at the Museum to pack equipment into our hired people carrier or ‘van’ as it became affectionately known, before the long drive north. This was also a good opportunity to get to know the fellow dipterists I would be staying with for the next week and their dipteron predilections:

• Duncan, our native interpreter/navigator.
• ‘New boy’ Dan, fan of bristly flies.
• Zoe, who spent a lot of time paddling for simuliids.
• Vladimir, fungus gnat aficionado.
• Not forgetting ‘The Boss’ Erica herself whom we rescued from the side of road after she was rudely dumped by an incompetent taxi driver!

After democratically deciding who would be sharing a room, copious wine and conversation were had before I retired, excited for my first visit into the wilds of Scotland. This began with being introduced to Dipterists Forum members and the customary discussion over maps.

Suggestions for a collective noun for dipterists?

We started with the Rothiemurchus Estate and on my first step into the Caledonian pine forest I was immediately struck by the wonderful scent of pine. The dipterists disappeared in all directions, and I began the sweep-stick head in net-poot ritual, although I had many escapes being distracted by the yummy bilberries (or blaeberries as they are known here) appearing in my net.

There were lots of the big hoverfly Sericomyia silentis, the first time I had seen live individuals; this impressive hoverfly became a familiar sight over the week, and always made a big fuss when caught in a net.

Sericomyia silentis having a wash and brush up on a leaf.

A long day of diptera in the field is inevitably followed by a long evening with diptera in the laboratory and so with a little bit of table rearrangement we soon had a makeshift lab in our cottage.

Must be the cosiest ‘lab’ I have ever worked in.

Our second day took us to Inshriach Forest, first stop Uath Lochans. These lochans, which our ‘native’ informed us meant ‘little lochs’ were breathtakingly still in the morning light, with a perfect reflection of the sky and mountains.

The beautiful Uath Lochans.

Around the lochans grew a colourful springy patchwork of heaths and other plants, mosses and lichens, dotted about with fungi including bright red Russula.

Bright red Russula fungi.

A handy boardwalk has been constructed around the boggy edges of the Lochans, from which I swept an amazing little fly. Running around in the pooter it looked like it was wearing boxing gloves and I was soon informed it was a shore fly (Ephydridae) called Ochthera.

Back in the lab I was encouraged to unhinge its raptorial forelegs, which inspire its common name, mantis fly. There is a lovely description in Colyer and Hammond’s Flies of the British Isles in their engaging style describing its “terrible fore-legs” with “tibiae curved and folded back upon the femora like the blade of a pocket knife, forming a trap from which the unhappy victim has little hope of escaping”.

Raptorial forelegs occur widely in insects, famously in the mantids, but also other groups of flies such as the hybotid dance flies which we found lots of during the week, and mantisflies, which confusingly are neither mantids nor flies but in the order Neuroptera.

The mantis fly Ochthera (probably O. mantis).

On day three we visited sites around Carrbridge, where I swept my first ever hippoboscid in Beananach Wood - these were Lipoptena cervi, the deer ked. They are very strange, flattened flies resembling lice, and must look even more louse-like when they settle down on a host and shed their wings; indeed Carl Linneaus originally classified them with headlice. Another peculiarity is that the females produce just one big larva at a time, nourishing it mammal-style inside their body, giving birth just when it is ready to pupate – aw.

Lipoptena cervi - I went a bit lepidopterist with this specimen, the wings are normally held over the abdomen, but you do get to see its bristly bum.

On Wednesday we headed to the seaside to visit Culbin Sands but unfortunately the weather was miserable (dreich in Scots-speak) so a midweek day off was announced.

Dan and Vladimir make a valiant effort to catch seaweed-inhabiting flies.

We met up with Duncan’s mum Sheena, aunty Moira, and friend for some tea and cake in Elgin before being brought to meet the Gordon clan and fed fresh homemade drop scones (Scotch pancakes) complete with homemade fruit preserves – heavenly!

Duncan's Aunty Moira and scones.

More deliciousness was to come when it was revealed that Duncan’s cousin Euan worked for BenRiach local distillery, so before long we were whisked off for a private tour and tasting session! Despite (or maybe because of) all the whiskey I managed my turn to cook dinner and all survived.

Euan presiding over the tasting session (whisky taxonomy?).

“And not a single fly was caught that day…” (Actually we did get a few!)

The fourth day of our trip arrived with better weather and surprisingly few sore heads, and we headed off to Insh Marshes which I was much looking forward to since I had heard great things about it, and I was certainly not disappointed. It was one of those sites that whisper “I’m special”.

On sorting my catch later I found my first ever pipunculid, or big-headed fly, which I like to describe as “massive head, all eyes”. Their heads are also notorious for falling off, so I was quite proud when I managed to micropin my specimen without casualty, only for this to be dashed when I later staged it.

Zoe and Erica sweeping their way along a valley in Insh Marshes.

Our last collecting day took us to some calcareous sites, and after nearly a week of acidic habitats it was quite a contrast to see some calcicole plants, many of which I am very familiar with, living as I do between two great ridges of chalk in Hampshire. Our first site was Fodderletter, a tiny but wonderful unimproved wetland SSSI huddled away on the Glen Livet Estate. Here we found lots of lovely big blowflies feeding on ragwort flowers, including the giant Cynomya mortuorum which caused much excitement, only slightly deadened by Alan Stubbs stating “oh yes it is quite common in Scotland”.

Handsome male Cynomya mortuorum with its lovely orange face and ‘mane’.

I was fortunate to catch a female on our next site, Creag Chalcaidh Quarry near Tomintoul. This was an intriguing site with springs spilling through the old quarry walls, producing chalky mats of algae. There were lots of unusual craneflies, which I don’t yet ‘do’ - their tendency for legs to fall off bothers my perfectionist nature, although this is soon to be addressed on a cranefly identification course.

Alan hunting rare craneflies in classic dipterist pose.

Our final site of the day, and indeed the trip was Bochel Wood, where I managed to catch an empid along with its meal, a bibionid. Since dipterists are, in my partner’s words “obsessed with genitalia” it would be remiss if I didn’t include a photograph of the impressive equipment possessed by this Rhamphomyia.

Crazy, crazy genitals…

On that note I’d better hand back to Erica, after raising a wee dram to great food, drink and company, and above all great flies!

A chilly Culbin Sands group shot.

With thanks to Daniel, Duncan, Erica, Vladimir, Zoe and the Dipterists Forum

Thanks also to Chris and the Angela Marmont Centre for use of the photo stacking system.

Recently the Dipterists Forum along with the Natural History Museum ran an Introduction to Diptera Course down in Wells, Somerset. The intention was to not only introduce the major groups of flies, detailing their fantasticle attributes (that is a real word when applied to Diptera), but also to give them time to collect and curate their own collection.

I therefore found myself, after a large amount of preparation from various people in terms of bringing together laboratory and field equipment, producing booklets etc, and booking vehicles (although it did transpire that I was a little limited on the last one….), taking 7 willing volunteers from London down to the West Country (and into Cheddar Land). We had two cars, one that was rammed with equipment – the other rammed with people, and we drove off full of the joys that only flies can bring…

Roger Morris, Stuart Ball and Alan Stubbs and I were running the course. Roger and Stuart had been running introduction courses for a while and so were old hands at it, and had many, many boxes of UK specimens for everyone to familiarise themselves with. Alan is basically a legend. He is the man who will sidle up to you with a hidden gem, usually something with long legs although some may be missing, on a scrap of paper with an almost illegible scrawl which is its name, tell you some interesting facts about the creature, smile and then sidle off again. This will go on for days!! It’s Diptera bliss….

So we arrive Friday afternoon to Cathedral School, where we had secured lodgings for the duration. I have gone back several centuries with the language as the house and school deserve that tone! (See below).

There was also a resident cat that used to just shuffle around in the sunshine, shifting from doorstop to doorstop.

The first evening consisted of introductory lectures on the basics of anatomy, terminology (always a pain that one as there is not enough consistency within Diptera) as well reading the landscape. Alan give the latter talk splendidly, detailing how we start with the geology of the countryside, then the soils, then the overlying vegetation and how all of this influences the matrix of flies that we are likely to encounter.

Alan, probably working on another legendary tome….

The real fun began the next day, after a good healthy (not) school breakfast to start the day (It is essential that all fieldwork is fuelled by generous portions of both food and nutty bitters, and an ice cream or two….). We gave a quick introduction to the types of field equipment you would need along side the various techniques you need to use them! Telling people to stick their heads in a net is all very well in principle but when faced with a net of buzzing, crawling insects many people suddenly become adverse to the idea!!

Lovely style and technique demonstrated by one of the students, Emma!

But out into the field we headed and then proceeded to catch as many flies as we could (by the second or third sampling trip, students realised that this was not a great idea as they all had to be pinned which involved a large amount of time!)

Whilst trying to avoid the natural hazards (rabbit burrows - not always successful) ...

... students went ‘a sweeping’ and ended up with the inevitable net hair….

And then it was back to the lab for sorting and identification time!

As well as spending the days sampling and then identifying, there were further lectures on common flies (not in the rough sort of way) as well as help with the curation of the specimens which included pinning, carding and avoiding impelling yourself with micropins.

I believe a good time was had by all if any of the comments that have come back are anything to go by;

‘My favourite moment from the Diptera course was when Alan Stubs did his impersonations of various Dipteran larvae, snaking around and representing mouthparts with rapturous arm movements. For me the most useful part was having all of the publications available, the reference specimens, and the new key to families which will come in most useful.’ – Mark Pajak

Mark with head in net.....

‘This course was the best identification course I have been on. Alan, Stuart, Roger and Erica were more then helpful, very patient and accommodating. It was a very relaxing but informative four days. I highly recommend this course and the dipterists forum for anyone interested in ecology. Flies underpin so much of our world, however it’s easy to ignore them because they are difficult to work with but this course really breaks things down and by the end flies seem manageable! I'm looking forward to doing more with the forum and more learning!’ – Megan McKerchar

Megan showing off flies..

‘Possibly my favourite part of the course was Alan Stubbs’ introduction to reading the landscape and geology of potential collecting sites. Primarily, I think this was due to, although being something that you consider before collecting, I didn't really appreciate to the extent that has been opened up to me after this.’ – Peter Wing

Peter and Pooter (sounds like a 1950's childrens TV program!)

I did not have to pay them anything…..

Check out the Dipterists Forum web site for further details on courses.