A long legged Dolichopus fly

I am an amateur naturalist trying to discover everything living in my garden.

For some time I have hankered after a garden pond (there are few things better for encouraging wildlife into one's garden). On a whim, I recently took the plunge (sorry, terrible pun!) and dug one. Though only a few weeks old, already I'm seeing enough life to keep me busy blogging long into the future.

Photo 1 shows two flies sunning themselves at the water's edge. There were several dozen around the pond.

The 'colony' was a constant flicker of activity and it was this that first caught my attention. Individual flies seemed to be attracted to movement and if another landed closeby they would quickly go 'into action', advancing rapidly towards the new comer. In a few cases one would even jump on top of another and the two launch into flight (at which point it was impossible to follow them by eye).

I observed a number of instances of one fly standing close by another and methodically rubbing its back legs together.  I've highlighted this with an arrow in photo 2. I recently wrote at length about  the courtship signalling behaviour of a related fly (Poecilobotus nobilatus) I found in my garden. I would like to think I was observing something similar here. Whether I was however, or whether it was just some coincidental preening I can't be sure (can anyone comment?).

So, how about the identity of my fly? Unfortunately, for the non-expert (=me!), identifying a fly is a decidedly non-trivial business. Firstly, a low power microscope is pretty much essential. Next, you need to be fortunate in finding an identification key. After that you need to be prepared to work through the copious technical jargon that the specialist keys will hurl at you. Finally you need the magic ingredient: experience!

How did I fair against this list? Well, I have a microscope; I was also fortunate to find the free online key by Dennis Unwin to the families of British Diptera, and "A Key To Swedish Dolichopodidae" by Igor Grichanov; For several hours I diligently applied myself to translating the jargon in the keys and scrutinising my fly's features. I was able to determine that my fly's "post ocular setae" (=bristles behind the eyes) are long and all of them black (see '1' in photo 3). Also, that the base of my fly's antennae sprout tiny hairs (see '2' in photo 4); that the shape of it's  "occiput" (= the back of the head) is convex (see '3') and that it sprouts two rows of "acrostichal setae" (=hairs down the centre of its back - see '4'). I worked through a dozen other similar features.

And the result of all my efforts? Well, further aided by a study of my fly's wings (see my discussion of insect wings here) I'm confident that amongst the 80-odd families of British fly, mine is a member of the family Dolicopodidae. Next, I'm fairly confident that of the 30-odd genera within this family, mine is a member of the Dolichopus genus. And finally, of the 51 British species within this genus (I got this number from the Dipterists Forum website)... well, I am not at all confident (!) mine is a Dolichopus ungulatus.

The one thing you can't look up is experience.

Common Darter dragonfly Sympetrum striolatum

I am an amateur naturalist trying to learn something about everything that lives in my garden.

Photo 1, taken back in Autumn shows one of Britain's forty-or-so dragonfly species. Referring to the magnificant colour photos in my copy of Britain's Dragonflies (Smallshire and Swash) I'm confident this is one of the commoner species, The Common Darter (Sympetrum striolatum). The yellow stripes down the legs indicate this one is a male. Adult Common Darters can be found on the wing from March through to earlier December if the weather is mild.

Two dragonflies were present the day I took photo 1. This is the first time I have seen them in my garden. About a kilometre from my house there is a large expanse of wetland however and there, at times, I have seen swarms of several hundreds.

To learn something about dragonflies I have been reading the book of the same name by Corbet and Brooks (New Naturalist Series). I particularly enjoy natural history writing that educates you about not only what is known, but also what isn't. The book is fully satisfying in this respect, concluding each chapter with a section 'Opportunities for Investigation', listing projects of genuine scientific value that any sufficiently motivated amateur might tackle.

The book opens with a discussion of habitat selection: Many dragonfly species are selective over the habitats they will adopt as breeding sites. Some demand flowing water, others still. Some require the presence of certain types of aquatic vegetation. Some will select a pond only if the trees on the bank are below a certain height. Etc. It's hypothesised that an adult arriving at a new location runs through a checklist of 'proximal cues': 'Is it water?' -> 'No', then fly on / 'Yes' then 'Is the water flowing?' -> 'No', fly on / 'Yes', then are there trees on the bank... What the cues are for many species isn't understood however. The fact that adults have been observed being fooled into, for example, trying to lay eggs into a wellington boot (!) suggests one line of enquiry might be careful experimental manipulation of environmental cues to try to work out those that appeal to different dragonfly species.

The topic of reproductive behaviour is a very rich one for study. The authors break things down into the four stages of Recogition (of a prospective mate); Sperm transfer; Guarding Behaviour; and Oviposition. Guarding behaviour is the habit amongts the males of many species (including my S. striolatum) of staying with a female even after she has been fertilised. The males of some species continue to grip the female by the head until she has finished depositing her eggs. Some even 'dunk' the female under water to assist her egg laying into the submerged stems of plants. An advantage of guarding from the male's perspective is that it prevents other males from coming along and displacing his sperm with their own. For the female there are presumed survival advantages: Two sets of eyes are better than one when it comes to spotting predators. Some species even go in for group oviposition, whereby half-a-dozen or more males/female pairs congregate in one spot to lay eggs.

There are a great many opportunities for amateur study concerning the larval stages of dragonflies. Dragonfly larvae go through a number of stages called 'stadia', moulting their exoskelton between each. The stadia for many species however, are simply not known. As the book puts it "there is an urgent need for keys to earlier stadia".

Some species go through all development stages in one year, others 'sit out' the winter in 'diapause', still others have the option to do either. Much remains unexplored concerning the factors that control the development rate of larvae and whether they overwinter or not.

Some dragonfly species lay their eggs several metres from the water's edge. How the first larval stadium (a minute limbless 'tadpole') makes its way from the egg-site to the water is again unknown.

Finally, there are many opportunities for studying the behaviour of larvae - their strategies for stalking different types of prey for example - that any suitably motivated amateur armed with a fishtank and plenty of patience could attack.

There is a great deal more that could be said about the study of dragonflies ('Odontology'). Part of me feels I ought to go on and write more here since I have not seen other dragonfly species in my garden and so may not get a chance to return to them on this blog in the future. On the other hand when I started logging my garden's visitors several years ago I never imagined I would find myself writing about peacocks and budgerigars. So perhaps I can afford to take the risk!

A fungus gnat , Sciarida (possibly Bradysia)

I am an amateur naturalist trying to learn something about everything living in my garden.

Buoyed up by my successful (?!) identification of a fly to species level in my previous posting, today I'm taking on a related, though tougher challenge: the little gnat in photo 1 (click on photo's to enlarge). This one was around in my garden mid-May last.

As I've discovered through writing this blog, to stand any real chance of identifying the smaller insects it's pretty much essential to have a microscope. This needn't cost the earth. Photo 1 was taken by holding a 'point and click' digital camera up to the eyepiece of a sub-£100 'DM2' stereo microscope. With 10x and 20x eyepieces this would probably suffice for a fair range of the needs of many amatuer naturalists though if you want to study the more minute structures such as mushroom spores, or the smaller pondlife, a microscope capable of 1000x magnification is needed. I have a (sub-£200) Westbury SP2 microscope which I've found to be thoroughly adequate for all my needs (the only minor drawback, for those in-the-know about such things, is I'm not certain this particular scope has the option to be equipped for 'dark field' operation, though this is a 'luxury' rather than a 'staple'). For anyone considering making a purchase, I have always been very satisfied with the service from Brunel Microscopes Ltd (I am unconnected with the company, and have received no payments for plugging them here!).

To set about identifying my fly I turned first to "A Key to the families of British Diptera" by D.M.. Unwin, available free here. This is designed specifically with the amateur in mind, being copiously illustrated to explain any technical terms. There are more than 80 families of British fly. The fact that my fly has long, thread-like, multi-segmented antennae immediately rules out more than 5o of these however, and places my fly in the nematocera, a sub-order of around 30 families. To distinguish between these its necessary, in part, to carefully examine your fly's wing. In my last posting on a crane fly I discussed the prehistoric origins of fly wings and the so-called 'Comstock-Needham' code for labelling up their veins. I'll not repeat this here and simply point out that I've labelled up the wing veins in photo 1.

With the wings of my fly in view, the key above pretty quickly bought me to a choice of my gnat being in one of two families: the Sciaridae or the Mycetophilidae. The 'decider' was the eyes. Photo 2 (taken from above looking directly down onto the antennae) shows my fly's 'left' and 'right' eyes, though this is a rather arbitrary choice of words since in fact the eyes are joined together to form one continuous band above the antennae. If ever you wanted an example of how 'alien' is the world of insects' senses, surely having eyes that join on top of you're head is one! Anyway, this 'eye bridge' decides against my fly being in the Mycetophildae and makes it a member of the Sciaridae. In searching for information on sciarid flies I came across two useful websites, the first dedicated to Sciariod flies, and the second, a list of free, online keys to different diptera.

The Sciarid flies are sometimes called 'fungus gnats', mushrooms being the larval food for some species. Mushrooms are not the only food however, and species have been reported emerging from a wide variety of substances from dead animals to birds' nests. Perhaps the most amazing thing I learnt about Sciarids in a short time searching is that the larvae of some occasionally undergo mass movements, thousands of them marching in columns several centimetres wide and metres long. I found an online paper reporting one such movement here [1]. It seems no one knows why they do this.

So far so good! Unfortunately, whilst identifying a fly to family level (Sciaridae in this case) is generally tractable, getting much further can be decidedly tricky. The first problem is that there are a lot of families of fly and finding a text-book or key that deals with yours can be difficult or indeed impossible. As luck would have it however, having become interested in flies and having something of a passion for natural history books, last summer I treated myself to some of the Handbooks for the Identification of British Insects from the Royal Entomological Society, amongst them Sciarid Flies by P. Freeman.

The book starts a little ominously:

[Sciard] taxonomy has always presented problems [...] the student has always been faced with a mass of similar looking species which he has been unable to group adequately.

Fortunately Freeman's book provides a detailed guide to identification, covering about half (according to this paper [2], as of 2005 there were 263 species of British Sciaridae in total) the British species across 18 genera.

So how did I get on sifting through the 18 genera of Sciaridae in Dr. Freeman's key? Well, On the basis of wing-vein shape and length, I was able to rule out 4 of the 18 genera; There was no sign of largish hairs ('macrotrichia') on my fly's wing veins, though there were tiny, downy hairs ( 'microtrichia'). This rules out another 5 genera; My fly has tiny spurs on its leg tibia (see photo 1). These are not 'distrinctly longer than the width of the tibia', ruling out the genus Corynoptera. After a little further work I was down to a choice between the genus Bradysia and the genus Lycoriella...and...I dropped my fly on the floor and lost it!!! On the basis of a couple of half-examined features, and the fact that Bradysia is the larger, more common genus, I'm going for Bradysia. But it all goes to show - you can't win 'em all!

Reference
[1] C. T. Brues, A Migrating Army of Sciarid Larvae in the Philippines, Psyche 58:73-76, 1951.

[2] Zoological Journal of the Linnean Society, 2006,146, 1–147. The sciarid fauna of the British Isles (Diptera: Sciaridae), including descriptions of six new species Frank Menzel, Jane E. Smith and Peter J. Chandler

A crane fly Limonia nebeculosa

I am an amateur naturalist trying to learn something about everything living in my garden.

My garden, along with the rest of the UK, is currently buried beneath a thick blanket of snow. Aside from a collection of tits on my bird feeder there's little sign of life. For this posting therefore, I'm falling back to a photo of a crane fly I took in summer (photo 1. Click on photo's to enlarge). Dozens of them swarmed out from amongst some garden ivy I happened to disturb at the time.

I know almost nothing about flies (diptera). Along with beetles, ichneumon wasps and various other orders of insect however, they strike me as offering rather "good value" to any amateur naturalist keen to make a genuine contribution to science since a) there are very large numbers of them (15,000 species of fly in Europe alone) b) they can display a rich and complex behaviour (see my posting on P. nobilitatus for example) and c) for countless species almost nothing is known. Take hoverflies for example. After hundreds of years of intense study by armies of naturalists there can be few countries in the world whose natural history has been so well catalogued as Britain's. Further, there are few flies as conspicuous as hoverflies. Yet even for these, a staggering 40% of the larvae of the 265 British hoverfly species of are simply unknown. In the U.S. its 93%. (This, at least, was the situation persisting in 1993 when my copy of 'Colour Guide to Hoverfly Larvae' (G.E.Rotheray) was published). Anyway, we're not here to discuss hoverflies. On to the star of today's show...

What makes a crane fly a crane fly? Well, firstly flies (=the order diptera) are separated from other insects by the presence of two vestigial wings called halteres. I've ringed these in photo 2. Next, the order diptera is separated into two sub-orders of flies called the nematocera and the brachycera. The split is based on the structure of the antennae - the nematocera all have long, thread-like antennae with more than five segments. You can see this in photo 3. The sub-order nematocera gets further subdivided into more than 70 families of fly, the crane flies amongst them. If you want a fuller flavour of how these families are separated, the redoubtable Field Studies Council has made a key to the families of fly by D.M. Unwin freely available here.

It used to be that all crane flies were clumped together in one family called the Tipulidae. At some point however it was decided to split this family into four, the Tipulidae, Pediciidae, Limoniidae and the Cylindrotomidae. I read on the (searchable) Catalog of the Craneflies of the World that worldwide there are more than 10,000 species of Limoniidae, 4000 Tipulidae nearly 500 Pediciidea and 70-odd Cylindrotomidae. Separating these families is a tricky job. To complicate matters further, recent DNA studies [2] are casting doubt on the very existence of the Limoniidae as a family.

The whole thing is rather confusing for the amateur (=me!) and for a long time whilst preparing this posting I despaired of being able to identify my crane fly. Fortunately, rescue was at hand in the form of an excellent set of test keys from Alan Stubbs I found on the Dipterists Forum website.

Before discussing these keys I need say something about how dipterists characterise the wings of flies: An influential theory, originally due to Comstock and Needham in the 1890's, is that way back in prehistory, a first primeval insect wing evolved. Exactly how this first wing appeared is still uncertain but a current theory [1] is that it evolved from the multi-branched external gills seen on the larvae of some aquatic insects such as mayflies. The veins in insect wings are hypothesised to be modifications of these gill 'tubes' (trachea). Anyway, assuming the existence of this ancestral wing, Comstock and Needham named the veins in it the Costa (C), the Radius (R), the Media (M), the Cubitus (Cu) and the Anal veins (A). As these veins fanned out through the ancestral wing they forked. So, for example, the radius vein, R, is supposed to have forked into five sub-veins called (logically enough) R1 to R5. No modern fly has retained all the veins of the ancestral wing, over millenia evolution has caused different families of fly to lose different veins. Which veins a fly has retained however is a very important clue to its identification.

Photo 4 shows the wing of my crane fly labelled up with the help of Alan Stubbs' keys above according to the Comstock Needham system.

There was one more piece of information I needed, namely whether my crane fly's palps (=little facial apendages) were long or short. Photo 5 shows they're short.

Armed with this information I was finally able to identify my cranefly as Limonia nebeculosa. Final 'clinchers' were the presence of 3-coloured bands on my fly's femurs (enlarge to see these in photo 1) and the sort of smudgy 'hoop' on the wing I've delineated with the dashed white line in photo 4.

Today's posting was a bit technical in places but I am pleased to have identified my first fly to species level. Only another 250,000 to go!

References

[1] Averof M., Cohen S.M., Nature 385, 627-630, 1997 Evolutionary origin of insect wings from ancestral gills.

[2] Matthew J., et.al. Phylogenetic synthesis of morphological and molecular data reveals new insights into the higher-level classification of Tipuloidea (Diptera), Systematic Entomology (2010), DOI: 10.1111/j.1365-3113.2010.00524.x

An Ichneumon wasp - Amblyteles armatorius

I am an amateur naturalist trying to learn something about everything living in my garden.

Hello! After a goodly absence I am back with some more of my garden wildlife. I hope there may be one or two of you out there still reading. Certainly my garden has not run short of new lifeforms to offer. Despite over a 100-species blogged so far, I have a long backlog of additional finds with more turning up all the time.

Photo 1 shows a magnificent insect I spotted resting on my hedge in late-summer of last year. The body was around a cm in length. Based on some similar images on the web I'm identifying it as an Ichneumon wasp - Amblyteles armatorius.


With tens-of-thousands of species of Ichneumon wasp worldwide and about 3200 in Britain alone, definitively identifying Ichneumons is a job for the specialist. Dr Gavin Broad is one such and has helpfully made available an online British checklist and a key to the sub-families of Ichneumonidae. You can download the entire 380-odd pages of the 1903-published Ichneumonologia Brittanica for free here. For any naturalist willing to grapple with the subject however, a supreme example of what can be achieved (and surely a candidate for "all-time greatest garden study") is given by Jennifer Owen. Her book, The Ecology of a Garden (Cambridge Uni. Press) records 15 years of painstaking cataloguing of the wildlife in a UK garden. During her studies Dr Owen discovered no fewer than 529 species of Ichneumon of which 15 were new to Britain and a staggering 4 were new to science!

From the comments above it will be understood my amateur's identification, based on a photograph alone, of my wasp as A. armatorius is to be treated with caution. It is certainly not the only European black -and-yellow striped Ichneumon as can be seen, for example, from the photo's here of species such as Ichneumon stramentor, I. xanthorius, Eutanyacra crispatoria and Diphyus quadripunctarius. For now I'm sticking with A. armatorius, as some of these others have yellow-striped antennae and other small differences, but I'm happy to be corrected by any of the experts out there.

Sadly, I have been able to uncover rather few details of the natural history of my Ichneumon. I have learnt that it is fairly common in the UK and the sole species in the genus Amblyteles. Adults apparently feed on pollen, that of umbellifers being a common target. In common with many other ichneumon's, the larvae are parasites of caterpillars, one target moth being The Yellow Underwing (Noctua pronuba). The larvae hatch inside the caterpillar and devour it from the inside. Other target moth species besides the Yellow Underwing are variously stated for A. armatorius. The scientific paper by Rolf Hinz (Entomofauna, 6(8), 1985, pp.73-77) disputes these claims however.

The paper above is in German incidentally, which is unfortunate if like me, you don't speak the language! (I found a free online copy of this paper some time ago, but have entirely failed to relocate it since. Anyone?). Since this was one of the very few learned articles I came across on A. armatorius however, I was determined not to be put off and came up with the idea of running the German text through Google's free, online automatic translation service. The results of computer translation are not always transparent. A German sentence that, in the original, I take to say something along the lines:
"I'm grateful to Messrs. G. and E. MannBausch Heidt of the Künanz Upland Bird-research Centre for supplying me with specimens"
gets translated as
"Messrs. G. and E. Mann Bausch Heidt from the research Künanz bird-house in the mountain, the procurement of the material allowed, thanks."
Nevertheless, with patience it's generally possible to get the gist and I'll certainly consider using this approach in future.

I appear to have digressed! When starting today's posting it had been my intention to say something on the amusing topic of the religious debate sparked amongst Victorians naturalisists by the life-style of the Ichneumonidae. Since I have written enough for now however, and since, with another 3000-odd British Ichneumonidae out there, I feel confident I will have other chances to revisit this fascinating family of insects in the future, I will leave my somewhat cryptic last sentence hanging in the air and bid you farewell for now.

A signalling fly Poecilobothrus nobilitatus

I am an amateur naturalist trying to learn something about everything living in my garden.

I have a plastic tub in my garden that has become partly filled with rainwater. Passing it last summer, my attention was caught by some flies busying themselves at the water's edge. A closer look revealed some fascinating behaviour: the wings of my flies were characteristically marked and the flies were solemnly raising and lowering them just as might an airport worker guiding a plane to a parking spot with a pair of semaphore flags.

I took some photo's though I confess I rather expected to fail to identify my fly. There are so many species (more than 15,000 in Europe) that to identify an unknown fly can be a tall order unless you're willing to spend hours with a magnifying glass and have access to some serious, specialist literature. Fortunately however, it turned out my fly is not uncommon, its behaviour having been noted by a fair few people, and an internet search led me to the species name: Poecilobothrus nobilitatus.

The stately wing-spreading displays of my fly are part its courtship display. As everyone knows, courtship displays are very widespread in the animal kingdom and can be fantastically intricate (one need only think of peacocks or the dance of Great Crested Grebes (video here)) . It's very natural to wonder what purpose such displays serve. Vast amounts of literature exist on this topic, with a great many unknowns and disputed theories. I don't have anything like the knowledge to comment expertly. My blog is about my learning something of my garden's natural history however, so a few facts gathered from some general reading on my part seem in order:

According to my copy of An Introduction to Behavioural Ecology (Krebs and Davies), the modern view is that, at the deepest level, courtship arises from a conflict between males and females over scarce resources. The point is that sperm are small and energetically 'cheap' to produce. Eggs, however, are larger and energetically more costly to produce and gestate. In the jargon, eggs are a scarce resource. Since eggs are, in this sense 'expensive, high value objects' it is worth males investing effort and energy competing for them. Equally, for females it pays to be 'choosy' when it comes to 'cashing in' the energy investment an egg represents.

The argument above might seem rather abstract, but its consequences are deep. Take the issue of mating with a wrong species: Some species of fruit flies for example, can and sometimes do, interbreed. Often this inter-species breeding results in sterile offspring however. From the perspective above, such parents have wasted precious time and energy. Clearly, it would have benefited them to have had some way to accurately check a prospective partner's species prior to mating. The elaborate courtship dances of some fly species (see here for example) may be just this: a way for females to check whether a male is of the correct species. From the female viewpoint, this avoids wasted energy on improper fertilization of her 'expensive' eggs. From the male point of view, although dancing costs him some energy, eggs are a scarce resource and having found some (i.e. a fertile female) it is worth the investment.

To take a second instance: Since eggs are a scarce resource it is important to lay them somewhere safe and where there is enough food available for the hatchlings. Some courtship displays - such as those where a male presents a female with some 'gift' (say, a morsel of food or a beak-full of nesting material) may be a way for the sexes to share the energetic cost of laying in a particular location (the female pays the cost of depositing her precious eggs; the male pays the cost of finding and presenting a 'courtship gift' that proves the location's suitability).

Yet another purpose of a courtship display may for females to test whether a male is a fit, strong individual, and able to pass on good genes to the egg. Actually, one needs to be a little careful before asserting a given courtship display is about a male demonstrating genetic fitness. To see why, imagine a species of bird that shows-off some glossy plumage during courtship. To say the male is demonstrating genetic fitness, makes an assumption that there exists an (inheritable) gene for glossy plumage for that bird. There may be, but on the other hand there may not. It could be that a male's glossy feathers are nothing to do with his genes but are due to him having been living somewhere that allowed him a good a plentiful food supply. The fact that females are choosing glossy feathers may be nothing (or perhaps only indirectly) to do with a male's genes, but because they say: "Food here is plentiful. It's a good place to breed". The point is not that advertising 'good genes' can never be a reason for a courtship display, simply that one cannot take it for granted as an explanation.

Anyway, in summary, a modern view is that courtship is about competition for resources between males and females. The successful male gets the benefit of the female's energy investment in eggs. In return females get an energy expenditure (=courtship display) from a male that relays something of benefit such as 'this is a good place to lay', or 'the male before you is the correct species', or 'the male before you has 'good' genes', or...(there are lots of other scenarios).

This barely makes a dent on a vast subject of course, and a great deal more could be written on the theory of courtship. This isn't the place to do it however, and instead let's get back to talking specifically about the my fly P. nobilitatus:

The best freely available online paper about my fly I came across was that of Zimmer, Diestelhorst and Lunau which describes the courtship behaviours of eight, so-called 'long legged flies' (Dolichopodidae), mine included. A number of these flies carry display 'badges' they use in courtship. Liancalus virens for example, also has signalling spots on its wings (see picture here). Neurigona quadrifasciata (here) uses foot markings to signal to females.

The paper provides a number of interesting facts about my fly. Firstly, experiments show that male wing span is directly proportional to body size: males with a big thorax also have big wing spans. During courtship P. nobilitatus males work to keep at a constant distance of 2.5cm from females. Taking these facts together, a plausible hypothesis is that female P. nobilitatus flies consider male body size important (as an indicator of a male's health status perhaps). By this argument the male's wing badges and constant- separation-dance are present in order to help females accurately estimate the body size of their suitor by sight.

Another intriguing suggestion in the paper is that males may have evolved signalling 'badges' to allow them to mate on the ground. The idea is this: some species of flies court in flight with males performing aerial stunts or hovering. Presumably these difficult and energetic winged manoeuvres may again allow females to assess health by looking at, say, wingspan. Now, suppose a male could 'con' a female's reproductive senses into thinking she was being presented with a hovering male when in fact both were sat firmly on the ground?! This is not as implausible as it sounds when we remember we are talking about a little fly whose intelligence and eyesight are not necessarily great! The female's reproductive senses may detect the 'beating' wings of a hovering male simply by whether her eyes detect (say) the outline of a wing and certain patterns of light and dark in the space before her. If a male could replicate these patterns whilst still on the ground, he might be able to fool the female's senses into a mating response, and at the same time save himself from the energetically costly business of hovering. The technical term for such cheating is 'sexual mimicry'. The paper concedes that this idea remains unproven for the long legged flies. I hope you'll agree however it's fascinating stuff and it all goes to show just how incredibly rich and intricate are the patterns of life just outside our front doors.

Helophilus pendulus hoverflies

I am an amateur naturalist trying to learn something about everything living in my garden.

Photo 1, taken back in September, shows two mating hoverflies resting on a leaf of my garden Buddleja bush. The characteristic brown stripes on the thorax quickly let me identify the species as Helophilus pendulus in my copy Hoverflies (Francis Gilbert, Richmond Publishing), an excellent monograph I've talked about before.

I assume the pair in photo 1 is male and female. Apparently it's normally possible to tell the two sexes apart in hoverflies by the eyes: The eyes of males touch at the top of the head, whereas those of females don't. Unfortunately this isn't true of Helophilus species. Why, generally, hoverfly sexes should differ in this regard, and specifically why they don't in Helophilus species, I can't imagine. Can anyone comment?

As I've mentioned previously, it's possible to distinguish hoverflies ('Syrphinae') from other flies by the veinature of the wings. In photo 2 I've zoomed in and enhanced the shot with my camera's software. Hoverfly wings have a 'false vein' (running approximately vertical in photo 2) and a section of vein at the edge of the wing that other flies lack.

In The Encyclopedia of Land Invertebrate Behaviour, the authors, R&K Preston-Mafham, describe male H. pendulus hoverflies as searching near flowers for females but often pouncing on other species of fly by mistake.

My copy of The Colour Guide to Hoverfly Larvae (G. Rotheray, Dipterists Digest 9) explains that the larvae of H. Pendulus thrive in farmyard drains and wet manure. Nice! My web searches also turned up a paper by one E. Stanley in the Veterinary Record 1845, 1(4) that describes finding an H. Pendulus maggot infesting the spinal marrow of a horse. By appearance they are a dark brown maggot with a tail as long as the body that acts as a breathing tube.

An obvious feature of hoverflies is the resemblance of many species to wasps and bees. Indeed, as explained in the extensive and very readable paper The Evolution of Imperfect Mimicry in Hoverflies by Francis Gilbert, at least a quarter of European hoverflies are mimics. Clearly, the mimicry is simply a matter of hoverflies trying to fool birds into thinking they are a wasp that will sting them....right? Well no actually, or at least it can be said the situation is far more subtle. As the paper above highlights the subject of animal mimicry is a complex one, much studied by biologists, and a topic where numerous questions and controversies persist.

Firstly, one should not assume that the 'warning colours' of hoverflies are, in all cases, a response to the threat of bird predation. There are plenty of other animals such as dragon flies, wasps and spiders will also eat hoverflies. Spiders have been shown to have an ability to recognise the threat posed by wasps in their web, and to treat them with greater caution than they do with other insects. At the same time, some experienced birds such as Flycatchers have been shown to be rather skilled at 'seeing through' the disguise of hoverflies - readily distinguishing them from wasps.

Next there is the issue of whether what we, with our human eyes, see as a resemblance to a wasp, is the same as what a predator perceives with eyes that might have very different characteristics to our own (different colour sensitivity etc.) Experiments studying the willingness of pigeons to peck at images of various hoverflies and wasps have shown that pigeons do broadly rank resemblances of hoverflies to wasps in the same way that we do. But there are exceptions with pigeons regarding Syrphus ribesii as the most wasp-like hoverfly of all, a view not shared by humans.

Next, there is the question of whether it is a bee's or wasp's sting that a predator is avoiding and that a hoverfly is "pretending" to posses. In fact, it seems that birds hardly ever suffer wasp stings and actually it is the unpleasant taste of a wasp's internal venom sack that some birds avoid. With Bumblebees (which some hoverflies mimic) the situation is more subtle still. There is some evidence that the sheer effort (in terms of wasted time and energy) involved in removing all the various hairs and largely inedible, chitinous, 'body armour' of a bumblebee is enough to put off some birds. Contrary to proclaiming its sting, the colouration of bumblebees (and their hoverfly mimics) may be a way of saying "I'm not worth the time and calories you'll get from eating me!".

This brings us to the difference between so-called Batesian mimicry and Mullerian mimicry. Batesian mimincry is the type of mimicry most of us imagine at first, whereby a harmless insect species evolves to copy the warning colours of a harmful one. By contrast, Mullerian mimicry involves two or more species that each have defences of their own, but nevertheless carry a common warning colour or form. Lots of bees and wasps all have yellow stripes for example. One can understand how this might arise: Suppose a predator has a bad experience with a harmful species. If that predator comes to associate the bad experience with a warning marking for that one species (yellow stripes say), then there's clearly potential benefit in other poisonous species adopting similar markings. By adopting similar markings however, one wasp species is not really 'copying' another, rather, both species are gaining benefit by evolving in parallel to advertise their venomous natures through similar body markings (multiple species settling on a 'common format' for advertising their individual danger signals if you will) . Now, in saying that hoverflies 'copy' wasps we are making the tacit assumption that hoverflies are harmless Batesian mimics. This is probably mostly the case. But it need not be universal. For example, it has been suggested that some species of hoverfly concentrate unpleasant tasting chemicals in their bodies through eating aphids that have been feeding on noxious plants. Such hoverflies would have their own defences (their noxious taste) and any evolved resemblance to say wasps, might then be an example of Mullerian mimicry.

The list of fascinating questions surrounding mimicry goes on. There is the question of the drawbacks of mimicry. Naively, it might seem there could little detriment for a species in 'wearing the clothes' of another. But suppose the venomous species being copied becomes rare. If a non-venomous hoverfly were to become more common than a venomous bee (say) it might be copying, what then? Predators would rarely (or even never) meet with the bad experience of finding that the prey in their mouth was the truly venomous one. After a time predators might simply stop associating the mimic's bright colours with danger. Indeed, the bright colours of the hoverfly mimic might become a positive liability, gaudily advertising the presence of a tasty snack! In summary, by choosing to copy the colours of another species, a mimic pays the price of shackling its population size that of the target insect being copied. Exactly the nature of the constraint (i.e. the mathematical relationship between the sustainable population of the mimic vs. the copied species) is a rich topic in its own right.

I could go on still further into a discussion of polymorphism in mimics, whereby a single species of say, hoverfly, comes in a number of different (colour) forms called morphs, and the benefits this confers. I've written enough for now however and so will leave this topic for another day, or, if you cannot wait for then, refer you to the paper above by Gilbert.

Gooseberry sawfly Nematus ribesii

I am an amateur naturalist trying to learn something about everything living in my garden.

I have a Gooseberry bush in my garden. In previous years I've had a good berry crop. But not this year! In May something attacked the bush, totally stripping the leaves. The culprit is shown in photo 1.

From closely similar photo's on the web I'm fairly confident this is the larva of the Gooseberry sawfly (Nematus ribesii). I should add my customary 'health warning' however: I'm not an expert on plant pests. As an amateur, you quickly learn that in natural history, identification of insects (fungi, spiders, lichen etc. etc.) solely on the basis of a photograph is always risky. There are more than a dozen species in the Nematus genus for example (see Bioimages site). I've found photos of only a handful. My caterpillar certainly looks like N.ribesii, but I don't know for certain it isn't one of the others. Can anyone more expert comment?

The damage done to my poor Gooseberry bush is shown in Photo 2. The branches would normally have been covered in leaves at this point in the year.

I did not spot any adult N. ribesii. From the photo's on Faroe Nature however it would appear they are squat, orange insects. This site has a drawing of the wing veinature taken from the book 'The Wings of Insects' (J.H. Comstock, 1918). (Wing veins are an important guide to insect identification - see my posting here).

In searching for articles on my sawfly I came across the admirable site of the Journal of Cell Science. This carries a large, searchable database of freely downloadable scientific papers. My searches turned up three on gooseberry sawflies (L. Doncaster, 1907, L. Doncaster 1905 and S. Shafiq, 1954). All get rather technical in places and I don't pretend to have followed all the details. From a quick read however, an interesting snippet I picked up is that eggs from both fertilised and unfertilised N. ribesii females can hatch but that larvae hatching from unfertilised eggs are overwhelmingly male. Eggs are laid in rows on the lower side of leaves at intervals of about a minute incidentally.

The main topic of the papers above relates to embryogensis i.e. the truly miraculous feat that Mother Nature manages of beginning with a single cell (an egg) and by a processes of repeated cell-replication and inter-cell communication constructs a complete insect (say) comprising hundreds-of-thousands of cells of countless types, all located in the right places, and all in an incredibly short period of time (about 4 days in the case of N. ribesii). Trying to undestand how she does this remains one of the great challenges for modern bioscience. It is perhaps fitting for this posting, that one of the most intensely studied creatures in all of science is a fruit fly (Drosophila melanogaster), flies being an ideal test-animal for such studies (along with nematode worms - see my post here) since dozens can be kept in a test tube where they will breed copiously and the offspring hatch rapidly. Armies of biologists have published innumerable articles about D. melanogaster - this site gives a flavour.

So there you have it, a seemingly humble garden pest with a rich natural history. Mind you, it might have been nice to have had a gooseberry crumble this year!

Dasineura urticae galls on a nettle leaf

I am an amateur naturalist trying to learn something about everything living in my garden.

I've previously blogged the nettles (Dioica urticae) growing in my garden (indeed, I guess some of you reading this may even now be tucked up in your nettle bed sheets!) and also described some of the capsid bugs (Liocoris tripustulatis) I found living on them.

Recently I've noticed evidence of a second lifeform feeding off my nettles, namely the galls in photo 1.

I am fortunate enough to be in possession of a set of a dozen-or-so volumes of Field Studies, a journal that was at one time published by the Field Studies Council. This admirable UK charity runs a wide range of residential study courses aimed at the amateur naturalist. The Field Studies journal is no longer printed which is a pity as it commonly used to feature keys for the amateur wanting to identify some of the trickier plants and animal in our fields and gardens, including (for present purposes) a key to British Plant Galls by Redfern, Shirley and Bloxham in the October 2002 issue. Fortunately, for those of you without old copies of the journal to hand, this key has been reprinted. You can purchase a copy along with various other gall guides from the British Plant Gall society here.

Redfern, Shirely and Bloxham list five arthropods and one fungal rust capable of causing galls on British nettles. The pouch-like swellings with slit-like grooves in their surfaces on the leaf in photo 1 indicate these are galls caused by the small fly, Dasineura urticae. Had I cut open some of the galls (I didn't) I might have been lucky enough to find some of the white grubs of this fly. Indeed, as I learnt from the very nice 'A Nature Observer's Scrapbook' site, I might even have found some predatory grubs from another species, laid there to eat the Dasineura urticae grubs.

I'm very far from being an expert in diptera (flies). From the Bioimages site however it seems there are several dozen British species in the fly genus Dasineura. This site has pictures of the grubs and galls of some of them.

I have only found one description of an adult D.urticae fly: My copy of Insects on Nettles (Davis, Richmond Publishing) describes a "very small fly with long antenna. Under a microscope an antenna looks like a string of beads...". Unfortunately I haven't been able to find a photograph on the web, although the Bioimages site does carry a photo of another Dasineura species (D. sisymbrii) which I guess may be rather similar since it too has bead-like antenna.

Sadly, that is as much as I have managed to learn about my mysterious fly. How and when the adults mate, how a female locates a host patch of nettles, whether she lays eggs or live grubs, how long the grubs remain inside their gall... I can only guess at the answers to these and a host of other questions. Another garden study-project to add to my burgeoning list!

Common Wasp Vespula vulgaris

I am an amateur naturalist trying to learn something about everything that lives in my garden.

Not everyone's favourite insect it must be admitted, photo 1 shows two wasps feeding on a rotten apple on my lawn (a habit shared with the mucor moulds I blogged previously).

The species here is the Common Wasp (Yellowjacket to those of you reading in the States) Vespula vulgaris, one of eight British species in the Vespidae family of social wasps. The hornet I blogged previously is another.

A number of the British social wasps are superficially rather similar and it can pay to take a close look at the face (photo 2) to be confident of the species. Were my wasp to be the not-uncommon German Wasp (Vespula germanica), for example, then it would have three little black dots in the centre of its face (mine doesn't). You can find a nice set of photos of the various British Vespidae species here.

Photo 2 also reveals my wasp is female: Her antennae have 12 segments (males have 13).

Wasps have been very common in my garden in recent summers and this is no doubt partly explained by the impressive abandoned nest (photo 3) I found in attic last winter.

Wasps have two pairs of wings, with each pair comprising a larger- and smaller wing. A pair gets 'zipped' together when the wasp lands so that it appears to be only a single wing. You can see this in photo 1. Taking one of the smaller wings and putting it under the microscope reveals that the analogy to a zip is well chosen: a row of hooks lines the edge of the smaller wing, allowing it to hook tightly onto the larger. Personally I never tire of looking at structures like this under the microscope. Any engineer will tell you how enormously demanding it is to machine mechanical devices to micron accuracy, yet mother nature is routinely able to grow fantastically intricate structures out of such unpromising materials as chitin or cellulose.

My efforts to learn something about Common Wasps led me back to the subject of 'worker policing', which you may recall I touched on in my posting on hornets. Briefly, it turns out that female workers in the colonies of many types of social wasp, bee and ant permit only eggs from the queen to hatch. Eggs laid by female workers are removed from the colony by other workers before they hatch. To the evolutionary biologist, this begs the simple question 'why?'. What advantage does the colony gain by only tolerating the eggs of a single individual (the queen)? Many learned papers have been written on this subject and I wouldn't presume a detailed understanding of all the technicalities but in brief, I understand the reason relates to so called 'kin selection'. It turns out that as a female worker, you are more likely to be closely genetically related to a grub hatching from a queen's egg than you are to one from the egg of fellow worker. Maximising all individuals' relatedness to each other is therefore achieved by preferentially rearing the queen's eggs.

Now, all of the above is as I explained it in my hornet posting. Whilst I didn't doubt the explanation, what I'd struggled to do there was to understand for myself in simple terms precisely why workers relate more closely to the queen's egg than to those of their sisters. In preparing this posting however, I came across the commendably readable More Than Kin and Less Than Kind by Douglas W. Mock. The key information I'd been missing concerns the way in which genes are passed down the generations in these many insects. Firstly it turns out what whilst female wasps each carry two sets of chromosomes (making them 'diploid' - just like us), males carry only a single set (they're haploid). Secondly it transpires that queens in insect colonies that practise worker policing, typically mate with multiple males. The sperm from all the queen's male partners is mixed together and stored in a vessel inside her body known as the spermatheca until needed to fertilise an egg. Which male's sperm fertilises which egg is then random. Taking these two facts together (the haploid/dipoloid male/female divide and the queen's 'random polygamy'), and working through some relatively simple genetics (anyone who remembers Mendel's sweet peas from school biology lessons should follow it), its not too hard to follow the chain of logic that shows that as a female worker born to a queen, you'll have a closer genetic resemblance to eggs from your mother than you will to eggs from your sisters.

And finally, I learn from a paper by Landolt et.al. that a good way to attract Vespula vulgaris wasps is to fill a vessel with acetic acid and isobutanol... of course, alternatively you might simply try eating a sandwich in your garden in August!

Bee Fly Bombylius major

I am an amateur naturalist trying to identify everything that lives in my garden.
Photos 1 and 2 (click to enlarge) show what must be the most dramatic 'nose' of any British fly.

A quick look through my copy of Michael Chinery's book Insects (Collins) and it appears that I've come upon a Bee Fly (Bombylius major). There are ten British species. B. major is the most commonly observed.

Bee Flies use their 'nose' (proboscis) to probe flowers for nectar. The length arises from their preference for hovering above, rather than actually landing on, flower heads. They do this presumably to avoid being ambushed by predators such as Crab Spiders that sometimes lurk behind flower petals.

Apparantly Bee Fly's are superb ariel acrobats. I didn't get a chance to observe this however since the one in the photo remained stubbornly perched on the branch of my garden apple tree. We'd had a few warm Spring days here in Oxforshire. On the day the photo was taken however it had turned cold and my Bee Fly was very sluggish (he/she was still on the same spot half an hour later).

I've not found a specialist UK site devoted to Bee Flies, but you can find a key to those of Canada here.

The best general description of Bee Fly natural history I've come across on the internet is that of Louise Kulzer. They have a complex life cycle. As above, adults feed on nectar. Their grubs are parasitic on solitary bees and wasps however. An adult Bee Fly lays it eggs near the burrow of a (true) bee and the grubs, once hatched, find their way into the nest and consume the food intended for the (true) bee larvae. Later, the Bee Fly grub undergoes a 'shape change' (hypermetamorphosis) into a carnivorous grub, and eats the (true) bee larvae.

That at least is a general description. Ideally I'd have liked to have found some more specific details about my species Bombylius major (What types of bee/wasp species it parasitises; How the Bee Flies tracks down a host-bee's nest etc.) but sadly there seem few descriptions on the web. I did find one other site that references a paper by one T.A. Chapman, specifically on the life history of B. major ...from 1878! (I haven't been able to find a copy)

My searches were not entirely in vain. I did come across the studies of Catherine Toft who has written about the ecology of Bee Flies in the Californian Desert, in particular observations on the foraging behaviour of two species. My amateur understandingof her work is as follows:

Back in the late 1960's, one T.W. Shoener argued that, other things being equal, females in nature should seek to maximise the time they spend feeding (on the assumption that taking in more energy through feeding translates into being able to produce more offspring). Males on the other hand should be 'time maximisers' i.e. beyond basic dietary needs, time spent feeding is in some sense 'wasted time' away from looking for, and breeding with, females. Dr Toft noted that two species of Bee Fly (Lorodotus pulchrissimus and L. miscellus) lent themselves very well to a study of this since the two species of fly live in an essentially identical environment, sharing the same desert habitat and even feeding on the same plant.

As it turned out, L.misecellus matched the Shoener prediction: females spent more of their days foraging than males. Males of L. pulchrissimus bucked the trend however. They spent exactly the same amount of time foraging as females. This is apparantly a feature they share with male moose! Although Dr.Toft offers some tentative explanations as to why this might be. The ultimate answer appears to await a deeper study however.

All of which suggests to me, that should you be an amateur naturalist reading this and searching for an amusing but scientifically useful 'project' to undertake in your neighbourhood this summer, you could do worse than to sit in a deckchair with a cold drink and a stop-watch, and time the foraging patterns of that little-known bug in your backgarden!

European Hornet Vespa crabo

I am an amateur naturalist trying to learn something about everything alive in my garden.

Photo 1 (click to enlarge) shows the handsome insect I found lying dead on a windowsill in my house some months ago. I am not expert at insect identification so at first I wasn't sure what I was looking at, but a little internet browsing and I'm confident I've found a European Hornet (Vespa Crabo): of the half dozen-or-so social wasps one might encounter in a British garden, the hornet is the only one with a distinctly brown coloured thorax. Much the most extensive introductory source I've come across online is Dieter Kosmeier's excellent hornet website.

Despite their fearsome reputation hornets are no more likely to attack humans than other wasps, nor is their sting notably worse. They are voracious predators of other insects however; a nest colony can take up to half-a-kilo a day. There are even records of hornets taking down pairs of copulating dragon flies (see Dijkstra et. al., Int. J. of Odonatol. 4(1),17-21, 2001).

Queen hornets hibernate over winter - the site of the Bees, Ants and Wasps Recording Society gives a record of a queen discovered beneath a rotting branch of cherry wood. She emerges around May and begins the process of constructing a nest and egg laying. By mid summer the nest is in full swing and may contain in excess of 500 individuals. Nests of one species of hornet (Vespa wilemani) have been recorded at altitudes of 2300m (Martin, Jpn.J.Ent.61(4), 679-682,1993). Come winter the nest is permanently abandoned (hornets do not reuse a nest the next year).

Figure 2 (click to further enlarge - if you dare!) shows a close up of my hornet's feasome jaws and, atop the head, the circle of small primitive light sentive 'eyes' (ocelli). Counting the number of segments on the antennae (=12) tells me my hornet is a female (males have 13)

A debate amongst professional naturalists concerns the mechanism and role of 'brood policing' in Vespa crabo. In brief the debate surrounds the question of why only the eggs of the queen, and not of the workers, are allowed to hatch (I was surprised to learn that the workers are not in fact sterile, and are quite capable of producing progeny). In the 60's the British evolutionary theorist W.Hamilton, argued mathematically that, other things being equal, in order to benefit their gene-line organisms ought to behave in ways that favour their close relatives (kin). Genetically however, a Vespa crabo worker is closer to its own offspring or indeed the offspring of a fellow worker than that of the queen. Despite this, workers ruthlessly seek out the eggs of fellow workers and discard them. Foster et.al. argue (Molecular Ecology (2000) 9, 735-742) that this may be due to the queen chemically controlling the 'minds' of the workers, hence the title of their paper 'Do hornets have zombie workers?' - although overall the jury seems still out.

Or at least that's my loose understanding of things. As I say often, I'm not a professional. I'm happy to be corrected and in particular I've not managed to follow the quantitative aspects of this debate. For example, Foster et. al. begin:

"In a colony headed by a singly mated queen, workers should prefer rearing sons (r= 0.5) and other workers’ sons (r= 0.375) to their mother’s sons(r= 0.25)'

I get the general idea, but can anyone give me a simple explanation of what these numbers mean and how they're calculated?

A Flesh-Fly, family Sarcophidae

I am an amateur naturalist trying to discover everything living in my garden.

Photo 1 shows a fly I found sunning itself on my bird-table late last summer.

I have no expertise when it come to fly-identification. With the help of the very nice colour plates in my copy of Insects (Michael Chinnery, Collins) however, I'm fairly certain my fly is a member of the Sarcophidae family of so-called Flesh-flies.

In general, identifying flies down to species level is a job for the experts. Page 27 of this book (The Sarcophagidae of Fennoscandia and Denmark, Thomas Pape), partly available online, gives you a flavour of what's involved. Dipterists spend a lot of their time looking at genitalia (!) -that of flies being an important aid to species recognition. I didn't subject my fly to the indignity of this, so can't be confident about its species, though from the book above a guess might be Sarcophaga carnaria (can anyone confirm or correct this?)

There are some 120,000 species of fly (Diptera), with 15,000 occurring in Europe. Chris Thompson's Diptera site contains a wealth of information, including specifics on the Sarcophagidae.Flies are distinguished from other insects in part by having only two wings, their hind pair having shrunk down to vestigial 'stumps' called halters.

There are some 2600 Sarcophagidae flies, about 300 occurring in Europe (this site lists them) and about 60 in Britain. As the name Flesh-fly implies both adults and larvae (maggots) are often associated with carrion, though in fact there is considerable variation in feeding habits across species: some concentrate on small corpses (this site has some closeups of an adult feasting on a dead caterpillar); some larvae are parasites of other insects; some predate snails, others earthworms; some species are able to live on a purely vegetarian diet. Sometimes of course, Flesh-flies become associated with human corpses. As a consequence the Sarcophagidae have been well studied by the science of forensic entomology which aims to get information about the time of a person's death by the rather grisly process of analysing any insects infesting the corpse.

The Sarcophagidae are viviparous (=females give birth to live young, the larvae). This book (Natural Enemies of Terrestrial Molluscs, G.M. Barker) explains this as an adaption to give the flies a speed advantage when it comes to getting their their young established on an ephemeral food item such as a corpse as rapidly as possible.

A final question I am left with is what purpose it serves my fly to sport the "zebra-like" black and white stripes on its back. Can anyone enlighten me?

Common Nettle Capsid Liocoris tripustulatis

I am an amateur naturalist trying to identify everything that lives in my garden

In my previous posting I described some of my garden's nettles, and it was on such that I discovered the little bug seen in the centre of photo 1 (click to enlarge). If you look closely you'll see a second individual a little lower down the nettle stem.

Photo 2 shows a magnified (40x) image of my bug. I can only speculate over what purpose it serves the bug to wear the rather smart, yellow, arrow-symbol on its back.
I had expected to struggle, and quite possibly fail, to identify my little insect, but the internet is an amazing thing! Ten minutes of searching against 'bug', 'nettle' and suchlike and I'm reasonably confident to pronounce my insect The Common Nettle Capsid Liocoris tripustulatis.

L. tripustulatis is a member of the insect family the miridae. From my copy of Insects of Britain and Northern Europe (M. Chinery, Collins) I learn that the miridea family is, in turn, part of the insect order hemiptera or the so-called true bugs. The true bugs have piercing mouthparts for sucking the juices of plants and can be distinguished from the beetles, by beetles having hardened wing cases ('elytra') that meet at a line along their backs without overlapping (see a previous posting here).

There are about 6000 true bugs in the family meridae. About 200 are found in Britain.

The true bugs are equipped with a drinking straw' (rostrum) for tapping the stems of plants and sucking out the juices. This is carried horizontally below the body and can be clearly seem in the 40x magnified image of photo 3 (click to enlarge).

Although I've come across various general discussions on the true bugs, I've been able to discover almost nothing on the specific habits of L.tripustulatis; A search of Google books turned up The Biology of the Plant Bugs (Wheeler and Southwood, Cornell University Press). The publishers have made a selection of pages available online and from a single sentence I learn that, along with their association with nettles, L.tripustulatis is known to need on nectar from buttercups. In addition, from a single sentence in my copy of Insects on Nettles (B.N.K. Davis, Richmond Publishing) it seems L.tripustulatis undergoes at least five larval instar phases. Aside from these facts however, the habits of my little bug remain a mystery to me. I'd love to know a little more. As I learnt from my readings on hoverflies, there are simply so many insects that often even the basic behaviours of many are completely unrecorded. My failure to find any substantial information on the natural history of L.tripustulatis perhaps indicates a good project for a keen amateur out there. On the other hand, perhaps much is already known and I've simply not looked in the right places. If anyone out there can help I'd be pleased to discover more about my handsome little capsid.