by Keith Farnish 
From the community blogs.
In the last article, we were looking at things that you can only see under a microscope, and it would have been wonderful to continue in that vein because — as much as it creeps a lot of people out — there is so much “out there”, and also “in here”, that is invisible to the naked eye. I could have had such adventures with phytoplankton in my book (although I do talk about them in Chapter 5), fungal spores, single-celled amoebas and all sorts of other minute organisms that contribute to the rich tapestry of life on Earth.
But for some reason I was attracted to Nematodes. Actually, by logical necessity I had to progress to something around a millimetre in size otherwise the size of the book would have got out of hand; but even at that scale I could have chosen all sorts of fairly familiar things, like seeds, springtails and zooplankton (tiny floaty animals). The thing that made nematodes so compelling was that I knew almost nothing about them — few people do — and yet they were considered by those in the know to be some of the most important creatures on Earth:
There is a certain difficulty in gaining realistic statistics about the variety and quantity of nematodes; after all, nematodes were not formally discovered until 1808, principally because they are too small to observe properly with the naked eye. Victor Dropkin made a more sober assessment than [Nathan Cobb, father of Nematology] of the nematode population in 1980, stating: “Take a handful of soil from almost anywhere in the world . . . and you will find elongate, threadlike, active animals. These are nematodes. Or catch a fish, a bird or a mammal almost anywhere in the world…and in most cases you will find some nematodes inside.” Although nematodes are aquatic animals, in that they need water to survive, the best place to find them is in soil. Simon Gowen of the University of Reading tells his students that in temperate grasslands there are around nine million nematodes for every square metre of soil – then the same students are expected to count them for themselves (not all nine million of them, I hasten to add), just to get an idea of what this means. That is an astounding figure for something that is not a virus or a bacterium, but an animal. This means that the lush grasslands of New Zealand that produce rich butter, high quality lamb and 150 thousand tonnes of wool each year, but only constitute 5.5% of New Zealand’s land area, also hold something like 132,660,000,000,000,000 nematodes. That’s 132 quadrillion, for those of you who ever wanted to know how large a quadrillion is. Compare this with the apocryphal (but believable, and slightly disturbing!) figure of one million spiders per acre of grassland, and you find that nematodes outnumber spiders by 36,000 to 1.
Anyone like to hazard a guess on how many nematodes there are to each human being? I worked it out at about a trillion, for every single human being on Earth! If that’s not interesting enough, there is also the fascinating division between what are considered “good” and “bad” nematodes: it depends to a great extent on whether you are trying to sell pest control devices and chemicals or not; but there are also a great number of nematodes that are unequivocally highly effective — more than almost anything else — at controlling the very “pests” that the agro-chemical companies make so much money out of. Not surprisingly, this relates very closely to the whole synthetic chemicals industry, as well as the often indecent world of biotechnology:
So why aren’t nematodes used all over the world, making most types of pesticide redundant? There are three reasons. First, not a lot of widely read research has been carried out on the usefulness of such nematodes; in fact many nematologists still believe that every nematode is a pest. Second, although nematode insect parasites were identified as effective controls in the 1930s, the availability of cheap, effective chemical pesticides in the 1940s caused this research to be largely ignored, and it was not until some chemicals were banned that research started up again. Finally, and linking these two together, it is clear from the continued lobbying of powerful companies like BASF, Monsanto and Syngenta, that the chemical industry will not give up without a fight. It is no coincidence that DDT was not widely banned until 20 years after clear evidence of its terrible impacts on wildlife was made public, and that the 2007 European Union REACH legislation – which enforces the control of hundreds of previously uncontrolled chemicals – took ten difficult years to come into force. Industry still calls the shots, even in an age when it is so obvious that natural ecosystems cannot cope with the torrent of chemicals being washed into them day after day.
Even with that said, there was even more to unearth in the shady and mysterious world of nematodes. It took me an awful long time to make the rather esoteric concept of Degree Days work on paper; but I had to because it related directly to Climate Change. I won’t try and explain it here, but after about four rewrites I finally made it easy to understand, and thus showed (I think) how relevant a warming world is to agriculture and our force-fed dependency on the global food market. The most surprising thing of all, though, was that it was possible to knit together the fate of something we now take for granted in the West — to the extent that in some countries the familar yellow banana forms an integral part of the cultural milieu — with Industrial Civilization’s obsessive quest for homogeneity, and just two types of nematode that could spell disaster for the world banana crop.
What strange and wonderful things nematodes are.
Keith Farnish is the author of “Time’s Up! An Uncivilized Solution to a Global Crisis”, which is published by Chelsea Green in the USA, and Green Books  in the UK. He is also the founder of The Earth Blog and The Unsuitablog. He lives in Essex, UK, with his wife, two children and a much-loved garden.