The word Collembola probably does not mean much to you at the moment but if I succeed in having my way you will soon be out looking for them. Collembola are soil and litter dwelling animals and they are often, nearly always in fact small, some are very small and others are definitely minute. At just over 0.2 mm long members of the family Neelidae are among the smallest known hexapods in the world, while the largest Collembola known to mankind are in the family Uchidanuridae and even they can only reach a length of 1cm or 13/32 of an inch. For this reason I will forgive you if you are not yet already fully aware of them as the wondrous creatures they truly are.

I have to admit that my introduction to Collembola came relatively late in life, not until I went to university in fact did I become aware of them. This is later than you may think because I was 30 when I finally got around to seeking a formal education. The experience was interesting and worth the effort if for no other reason than that it allowed me to get to know the Collembola.

In my second year as an undergraduate I attended an ecology course which, amongst other things, involved us doing a comparison of the diversity of the flora and fauna of a well kept and mown lawn with a piece of what was basically waste ground cut approximately every couple of years to stop shrubs and trees taking over. This was in fact a very simple and successful exercise and I would highly recommend it to teachers. The organisms caught do not need to be identified to any great detail for the difference between the two sites to be obvious. Any way, a major part of this survey was the putting out and collecting of numerous pitfall traps.

Pit fall traps are a major ecological tool, especially they are of use to low budget and amateur ecologists because they involve no high technology though a reasonable stereo microscope can be useful for later identification. They come in a large variety of styles and forms, which relate in diversity to the requirements of the experimenter. Basically they are a hole in the ground with a container inside it. The container can be protected from the rain by a cover 1or 2 cm above ground if so desired, it can have a funnel at the top to guide organisms into and to hinder their escape from the trap. Also it can have either crumpled cardboard as habitat space, or a killing agent (such as car antifreeze) to prevent the unhappy residents from eating each other. Exactly how you set up your pitfall traps depends on you, what your aims are and your experience. Effective pitfall traps for schools or personal interest can be made from empty 1.5 litre water bottles. Simply cut the top third of the bottle off, make 3 or 4 vertical slits in the cut edge of the top third then invert it and place it into the bottom 2 thirds such that it makes a funnel. This should then be buried up to the rim in the soil and checked every day or so for inmates, if habitat creating cardboard has been provided these are more likely to have all their limbs and can after identification, or merely after admiration, be set free. An awful lot of good scientific data has been collected through the use of pitfall traps that are little more drink tumblers so do not dismiss the idea of using them just because the apparatus is simple.

At university I was among the few who had any real interest in the subject of animal biology outside of marine mammals and furry cuddly things. This had definite benefits which included practically free access to all the samples from the pitfall traps because nobody else really wanted to be bothered trying to ID the specimens. Having been an amateur naturalist for years I had a distinct advantage here anyway as I had far more experience of most of the groups involved than most of the students. So I and the one or two other interested parties counted our way through 60 pitfall traps worth of samples and as we were doing this I slowly fell in love with the Collembola.

The Collembola were always the easiest creatures to count in the samples because unlike the rest of the specimens they tended to float on the surface of the alcohol they were preserved in. This is the first thing that brought them to my attention, however I was soon captivated by their beauty. They come in a great range of colours, green, yellow, brown, golden, purple, pink, silver with rainbow hues, blue etc. Except for the silvery ones the colours are pastellish and very pleasant on the eye and when they are all aggregated together on the surface in the samples, floating above the greys, browns and blacks of the other arthropods which have sunk below the surface of the 70% methanol they were most attractive. Later I was to discover the joy of watching them while they were alive, which was much more enjoyable than looking at dead specimens. At the time however all I had was this budding fascination, I raced off to the library and found a copy of a monograph on Collembola and Thysanura published in 1873 by Lord J.L.Avebury (1832 to 1913). The book contained a series of very beautiful colour images, all painted especially for the book by a deaf and dumb artist by the name of A.T.Hollick which helped feed my new love. This is a lovely book in many ways, with a feel of real devotion to learning and a love of the subject that is hard to find in many modern publications. It is worth looking up a copy if you have any interest in Collembola, it holds a place in history because it is the first mention in literature of the term Collembola. Unfortunately not all the copies published include the paintings by Hollick. To explain the origins of the name I have to include a little anatomy. Collembola possess only 6 segments to their abdomen, one of the things that separates them from insects which normally have more than this, especially in primitive groups. On the first abdominal segment is the ventral tube (an organ for the absorption of moisture). It is for the possession of this organ that the group have earned their name in the mistaken belief that the 'peg-like' ventral tube was used by the animal to glue itself to smooth surfaces; thus kolla, which means glue and embolon, which means a peg, combine, and when Anglicised give us Collembola, the name by which they are still known in scientific circles.

Apart from this excellent if now outdated book, (Lubbock lists a total of 130 species) I found one other work on Collembola in general, this one from USA and a Key to European species in German. I read all I could of these and then spent some spare time trying to identify various specimens to species level. Being an undergraduate however leaves little time for using difficult foreign language keys and I was also trying to record woodlice, triclad flatworms, hoverflies, aculeates, carabids and millipedes, as well as write articles for the BugClub Newsletter, go bird watching, maintain some semblance of a social life and get my degree. Inevitably Collembola fell onto the back burner of my life. Then I graduated with honours and spent a year writing and working on ants before being offered a Ph.D. on soil invertebrates, specifically Collembola and Acari. Acari are mites, small to minute arthropods, members of the class Arachnida and thus related to spiders, but only to the sort of degree that Cockroaches are related to Butterflies. I wasn’t nearly as fascinated by them, but a chance to renew my love affair with Collembola could not be turned down, even if it meant giving up my home and my gardens.

So off I went to wet and windy, but also very often beautiful and wondrous Dartmoor. Academically this was the worst move of my life, but otherwise was a positive experience because it allowed me to renew and expand of my love for Collembola. I was able to set up cultures of a number of species and spent numerous happy hours watching them wander about their small but fascinating lives. Different species have very different ways of responding to the world. Some are slow and plodding moving around their small plots for all the world like a heard of miniature cows. Others are quick and active, moving much more intently and as likely to leap away at the slightest provocation or disturbance as they are to move slowly. These I likened to gazelles.

I have not limited my self to herbivores when seeking larger animals to compare Collembola with. Species like Orchesella cinta and particularly Orchesella villosa are definitely leonine in appearance with a large golden mane. Other species are not readily identified with any larger animal. Especially the Sminthurids who have too rounded and squat a body to be equated with any larger animal. Members of the genus Papirius are particularly colourful with intricate designs painted by some inspired miniatures artist all over their abdomens. Papirius ornatus as seen on the cover of this book is perhaps the finest example of this art. As a pleasant surprise it was relatively common around the sheds and yards of the research institute I was working in. No discussion of the beauty of British Collembola (it is an unfortunate fact of life that I have not yet had the chance to appreciate the beauty of any non-European species) would be complete without mentioning Pogonognathellus longicornis, until recently known more reasonably as Tomocerus longicornis. This is a relatively large (to 6 mm) and common species in Northern Europe, it is not overly colourful but has the delightful behavioural habit of curling and uncurling its antennae, something which, because it is beyond the capabilities of ordinary insects, always used to amaze me.

To get back to the gazelle like leaping of some surface dwelling species I need to explain a bit more basic biology. As I have already mentioned Collembola have only six abdominal segments, other primitive insects have nine to eleven. On the first is the peg-like organ called the ‘ventral tube’, on the third is the minute tenaculum or hamula which I will get back to in a minute and on the fourth is the 'furca' . This is a forked springing organ from which the creatures derives their common name of "springtails". A Collembolan normally holds its furca folded up under its abdomen, sort of like a dog with its tail under its belly. The furca is a spring however and in order to keep it in place Collembola have a hook or clasp, this is the tenaculum of the third abdominal segment.

It is the furca, or at least the results of the furca being used that will be most noticed about disturbed Collembola. Under the microscope Collembola simply disappear when they jump, launching themselves like tiny rockets clear out of the field of view. As with all very small animals their feats of strength on the physical plain seem prodigious to monsters like us on whom gravity has such solid grasp. A two mm long species such as Entomobrya dorsalis can jump a distance of more than 16 cm or 80 times its own length. The stresses small animals can withstand would tear us apart. Sminthurus viridis a cosmopolitan species that is occasionally a pest of lucerne takes off with an acceleration of 970 m s-2, while Allacma fusca takes only 12 milliseconds to become airborne from the start of its jump. All this speed and sudden devastating acceleration is not just for the fun of it. Collembola live in a jungle like world and have little in the way of defence mechanisms besides this rapid retreat. However even this is impressive get-away does not guarantee success, there are species of both ants and ground beetles which have specialised in catching Collembola and make quite a handy living at it. Of course not all species are quite as athletic as those I have mentioned here, these are the Olympian record holders of the order and well deserve their laurels, there are many other lesser mortals among the Collembola. Many species in fact, having taken to living below the surface of the soil where jumping results in head aches and not escape have reduced or completely absent furca.

Collembola are exceedingly successful organisms, and as such it is fitting that we should learn more about them. There are more than 6 000 known species in the world and some people estimate that there may be as many as 50 000, they live just about everywhere, in the canopy of tropical rain forests, on the beach, in tidal rock pools, on the surface of fresh water ponds and streams, in the deserts of Australia and in the frozen wastes on Antarctica. In fact Collembola have a more Southerly distribution than any other hexapod (84º 47’ S.) and can survive temperatures less than --60 C.

Like everyone else however they prefer warm places to frozen wastes and most species occur, and are most numerous in, warm damp places. Many live in the leaf litter and or the soil. The species which live in caves or deep in the leaf litter and or the soil tend to be white, have and reduced or no eyes, as well as the reduced or absent furca already mentioned. The species that live in more open environments are more coloured and are often very beautiful. Most species live for a year or less, however some live considerably longer and the record for long life in the laboratory is 67 months for a specimen of Pseudosinella decipiens. Most Collembola feed on the fungi and bacteria found in rotting organic matter but many arboreal species (living in trees) and epidaphic species (living on the surface of the soil) also feed on algae. Others feed on other plant materials and in some places particularly Australia Sminthurus viridus as already mentioned is a pest of lucerne crops. A few other species are carnivorous feeding on Nematodes and in a very few cases other Collembola.

Collembola continue to moult about once a week even after they have reached sexual maturity, they don't however continue to increase in size which is the normal excuse for shedding a skin. I had no real explanation for why they should do this in 1996 when I was studying them and I still have no explanation. Moulting is an energetically expensive procedure and one would have expected 400 million years of evolution to have been sufficient for them to have lost the habit if they had no use for it. Therefore I am presuming that it does still serve a valid purpose even though we humans have been unable to discern it. Collembola stand around doing apparently nothing while preparing for each moult and the frequency with which they moult can mean they spend a great deal of their lives doing physically what appears to us to be nothing. They need to have an empty gut before moulting because like their close relatives the insects they shed part of the stomach lining with their external skin. Because of this females loose any sperm they have stored from a previous mating and have to mate again after each moult.

Many species are known to have an aggregated or clumped distribution, particularly in the soil and this may well be to do with mating, for small practically defenceless creatures finding a mate is much easier if you live in a group. In many species sex is strictly a non-contact experience, males deposit a spermatophore normally at the top of a hair or petiole to keep it clean for a the females to find when they need it. In some species the males appear to deposit these at random, wherever the urge takes them so to speak. Others slightly more in tune with the concept of social activity wait until finding a receptive female and then deposit some nearby. In some species competing males have the delightful habit of eating the spermatophores of their competitors before setting up there own in their stead. Finally amid all this decadence there are species such as Bourletiella hortensis which are slightly more conventional and go in for a brief courtship before the male makes a spermatophore available to the female, while in Sphaeridia pumilis the male uses his third pair of legs to transfer a drop of sperm to the females genital opening. The eggs are deposited singly by some species and in large masses by others, these masses may be contributed to by a number of females. A female will lay about 90 to 150 eggs during her life, though obviously there is considerable variation between different species.

Collembola are strictly speaking not insects, though they have many of the same characteristics, being small arthropods with six legs which makes them hexapods. However there are some very significant differences between insects and Collembola. They are in fact a separate branch from the main trunk of the ancestral organisms that evolved into the first insects. The up shot of this is that though just about the only place you will find them is in entomology textbooks they are now known officially as hexapods. Strictly speaking all insects are hexapods as well, in the way that all gerbils are rodents, but not all hexapods are insects much the same as not all rodents are gerbils.

Collembola are very ancient organisms and were around when insects were first coming into existence. The oldest known fossil Hexapod Rhyniella praecursor is a Collembola from chert of the Lower Devonian era. This fossil is over 400 million years old and is the oldest known fossil hexapod. To put it in a nutshell, Collembola were around long before any of the present day groups of insects evolved, they have seen the dinosaurs come and seen the dinosaurs go and they still seem to be enjoying life.

Collembola are often exceedingly abundant in leaf litter and soil, in 1935 a gentleman by the name of Ford found 60 000 Collembola per m-2 in a meadow near Oxford England while more recently Collembola in numbers as high as hundreds of thousands per m-2 have been recorded from soils in India, Japan, Norway and England. In tropical soils they may amount to more than 50% of the total number of soil animals. It is best to remember then, when you are out walking in the wilds or working in your garden, that you are considerably out numbered by Collembola, so be nice to them.

And so we are lead inevitably into the wonders of the soil and its ecology, no I am not being sarcastic, merely wondering as I type this how much to leave out. Soil ecology is a fascinating and much under publicised field of study, and though I feel I have said enough about Collembola to satisfy most people I am compelled to say a little more about that amazing substance ‘the soil’ that so many Collembola call home.

However solid an uninviting the soil may look to you and me it is not an indivisible block of sameness but a highly heterogeneous environment. It is filled with innumerable aggregations of matter, organic and inorganic interspersed with an equally innumerable number of small spaces called pores. For most organisms life in the soil is lived on a micro scale, these small pores are large habitable spaces to the organisms that use them. Living in the soil is a bit like living in an endless series of interlinked caves, a huge 3D matrix of high class accommodation, with plenty of food, and very stable environmental conditions.

The soil has been described as the "Poor Man's Rainforest" such is the amazing diversity and complexity of the life that exists there. This is particularly true of temperate soils. Every step you take along a natural path, be it grassland or woodland, you have beneath your feet a far greater diversity of species and immensely more individuals than you can see around you. Like a Tropical Rainforest the temperature in the soil is fairly constant, much more so than the air above. A couple of centimetres down the soil rarely if ever freezes, even when it is twenty below above. The humidity, which is very important to many smaller organisms, is high and much more constant than on the surface.

The soil is not only a full time home to millions of these small animals but is also a temporary escape from the elements for many others, huge numbers of beetles, flies, and moths lay there eggs in the soil and have there larvae live there, as well as this many bees and wasps make there nests in it. These larger residents, as well as the occasional vertebrates, rabbits, prairie dogs etc., inevitable move the soil around and make, what are to the smaller residents, large spatial changes in the soil structure. In terms of bulk soil moved however all of these animals are relatively unimportant. The real earth movers in this world are earthworms in temperate soils and ants, millipedes and termites in tropical soils.

In some places in Britain there are 1 ton earthworms per acre who will move well over 10 tons of soil per year. Earthworms were quite aptly described by Aristotle as '...the intestines of the earth'. Numerous soil scientists have been equally fascinated by the amount of work done by them, Charles Darwin said of them "It may be doubted whether there many other animals which have played so important a part in the history of the world as these lowly organised creatures". Earthworms are miniature topsoil factories, earthworms make soil, all other living things eventually pass through an earthworm on the way to becoming soil, and nearly every atom in your body has been in an earthworms stomach before it was part of you, (salt is an exception). Earthworm castings are rich in all the minerals necessary for plant growth, in a water soluble form so that they are immediately available for plant use. All the soil you have ever seen has passed through the stomachs of numerous earthworms to become what it is. The best way to deal with those unwanted earthworm casts on your lawn is to collect them and use them as potting compost, no manufacturer in the world will ever be able to make anything even half as good for young plants to start their lives in. Soil is a very precious and valuable commodity, all of our arable crop based economy as well as the whole world of grazing animals is dependant on its existence. When you realise that it took some earthworms between 500 to 1000 years to produce the first 3cms of it, you can accept that it is definitely something to be treasured and respected.

The world of the soil, as with so many worlds is truly beyond our imaginations. As I said before the number of organisms living in the soil is immense. A few figures should suffice to convince you of this. Please bear in mind that there is a huge variety of soils across this globe and they all differ in the nature and number of organisms present, the following figures are just some examples of what can be found. Starting with the smallest inhabitants and working our way up we find that there can be 6 to 10 billion bacteria per m2 , or 8.65 tons per hectare. There can also be 1 million to 2 million km of fungal hyphae per m2. (These are English billions or a million millions, note that 8.65 tons per hectare = 3.5 tons per acre.) There are often up to or even more than 1000 species of fungi in a woodland, most of these are never seen by people even those like myself who like to go out in the Autumn to see what nature has offered us to eat. About 90% of all plant material that fall to the ground is broken down by these two decomposers, the rest of the organisms living in the soil are feeding on the bacteria and fungi or on each other.

Many people may be quietly surprised to discover that the soil is home to millions of Protozoa. Protozoa come in a variety of forms but they all share a predilection for feeding on bacteria and fungi as mentioned above. Two forms of protozoa dominate the soil environment, amoebas and ciliates. Of these amoebas are about 100 times more numerous than ciliates. In total there may be as many as 10 million protozoans per m2 of soil. Forest soils are always more densely populated with micro-organisms than grassland soils. This can equate to 30 kilograms of protozoans per hectare in Grassland soils and 200 kgs per hectare in Woodland soils.

Moving on up the scale of size, but not very far we find that Nematodes, sometimes referred to as round worms which feed on all of the above as well as plant roots occur in densities 10 million per m2 in grassland soils 30 million per m2 in woodland soils. Next come Enchytraeids also known as potworms here we have only 200 000 m2 in grassland soils and I have no data for woodlands. enchytraeids are described as feeding on dead plant material but in fact they will be digesting the bacteria and fungi living in the rotting plant material the same as protozoans and nematodes. Enchytraeids are however to big to collect these minute creatures so they eat small chinks of leaves instead. This is pretty much the same for earthworms. Mites like Collembola are extremely numerous in the soil and can occur at densities as high as 500 000 per m2. Unlike Collembola they have very diverse feeding habits and eat just about everything as a group. Many species are carnivorous seeking out and eating other animals slightly smaller or similarly sized to themselves. As I have already said many species are particularly fond of Collembola. Their feeding methods are not particularly attractive to our human sensitivities, though what an intelligent Mite would think of the human animal husbandry techniques that resulted in the spread of BSE I can not imagine.

Finally to finish up this little list of numbers a square metre of good uncultivated soil can also house up to 3000 woodlice, 3000 beetles, 3000 symphyla (primitive insects just about only found in soil), 500 tardigrades or water bears, 480 spiders, 450 slugs and snails, 150 centipedes and more than 100 millipedes.

If all this has made you want to be more careful where you put your feet take into consideration that if you are following a trail of path the soil beneath this will be compacted, meaning that the all important spaces will have been squished out and it will therefore hold far fewer organisms than soil where feet, human or otherwise are a less frequent occurrence.

You can perhaps now realise that the soil, as dead and uninviting as it sometimes looks is really a thriving and vital habitat. One that that can be described as having its own life on the environmental life. Like all living things it is dependant on the checks and balances that have evolved over the millennia to maintain its health. It is a simple truth that 99% of time the more organisms there are living in the soil the healthier that soil is. Also like any other living thing the soil needs a constant inflow of energy. For most natural soils this is regular inundation of plant material from dead and dying plants as well as from seasonal loss of leaves in temperate woodlands. Unfortunately human farming techniques tend to keep the soil barely alive, struggling to maintain the simplest communities on a threadbare and poorly balanced diet. The old habit of leaving fields fallow every year or two went a long way to relieve the depredations human farming practices made on the soil, especially if the soil was sown with a legume prior to this year. Modern fertilisers may feed plants but they do little for all the other organisms that are so important to the soil as a living experience. Ancient wisdom knows that greed is attitude that eventually gets you from behind, something that modern science is just learning to appreciate in the philosophies of Deep Ecology with their stress on the interrelated and interconnected nature of the world we live in. For small time gardeners the habit of mulching your garden and flower beds can do immense amounts of good to the soil we so often take for granted and I can not recommend it highly enough.

As a final note I should mention that some species of Collembola are relatively easy to keep in culture and as such can make excellent pets. As pets they are far superior to dogs, cats, gerbils or budgerigars. the reasons for this are that they are easy to keep, require practically no expense to keep, they do not attack or breed with the local wildlife, can not hurt the owner in anyway, or annoy the neighbours and they can always be released into the wild if they are no longer required. On top of all this they are far less likely to suffer stress from being kept in captivity than birds or mammals, mostly this is a result of their small size.

The best way to obtain some Collembola is to go out and look under odd pieces of wood in mildly damp parts of your back garden or nearby playing field. If no pieces of wood are around supply some, old well rain washed wood is best. Collecting them is best done with a pooter (see the chapter Antipathy in this book). If you are more serious, or require species that are not so capable of leaping out of their containers you will need to construct a Tullgren-Berlese Funnel. This is not really difficult, simple follow the steps for preparing a plastic water bottle for being a pitfall trap, only before you invert the top tie a piece of loose mesh cloth (holes of 1mm across are ideal) over the mouth of the bottle and add a piece of damp paper towelling to the bottom of the bottle. Next add some top spoil or leaf litter to the inverted top and stand the whole lot under a desk lamp. The light and heat of the lamp will dry the soil or litter out and the residents will descend deeper into the soil in an attempt to escape, eventually they will fall into the bottom half of the trap where you can collect them at your leisure. You will naturally collect other organisms along with your Collembola using this method, as most of these will eat Collembola, especially the mites I do not advise you to keep them in the same container.

As a cage or container you will need something like old margarine container, or one from the delicatessen that had 250 grams of Kalamata Olives in before you ate them. But some fine sand, or for burrowing species 5 mm of plaster-of- Paris in the bottom, It is a good idea to add a small amount of ground charcoal to the plaster or sand as you mix it up to help keep the air clean. It is also a good idea to make several extra containers so you have some to tip the Collembola into when you want to clean the ones they have been living in, with sand based containers you will have to pooter them out when you are changing homes. Leave the plaster for a few days before putting any Collembola in and then let it soak up as much water as it can before you but the Collembola in, the sand should also be well damp. Some small pieces of old wood and bark will make life easier for everyone. At least one piece of bark with some algae on it is a good idea. Keep the lid on tight when you are not watching them and add a couple of drops of water after having the lid off for a few minutes as most Collembola die from drying out very quickly, but be warned they will also die from too much water, so keep the plaster-of-Paris damp but not swimming.

Your new pets will of course need feeding. In the wild Collembola will feed mainly on fungal mycelium (that is the part of the fungus you do not normally see, what you call a mushroom or toadstool is actually the fungi's fruit) and algae. In captivity they will eat just about anything, but will thrive on dried whole/live yeast, just sprinkle in a little at a time. If you have more facilities you can grow various fungi on agar plates and then let the Collembola feed on this. They will also eat their own faeces quite naturally so don't worry if this happens they are actually digesting the micro-organisms that live on the half digested food in the faeces and not the faeces themselves. Some species will eat their own exuviae (shed skins) but if they do not you will have to remove them, and any dead bodies, from the container with a fine paint brush otherwise they will breed undesirable fungi. That is about it really, the rest as they say is pure pleasure.