Biologue

Article by
Heather Proctor, Australian School of Environmental Studies, University of Queensland, Nathan 4111 QLD
David Walter, Department of Zoology & Entomology, Griffith University, St. Lucia 4072 QLD

Soil systems support all of terrestrial life, and contain an extraordinary diversity of organisms; yet, we know more about freshwater faunas than those of the ground we tread. Soil has been described as "the poor man's rainforest" and "the last biotic frontier" because its inhabitants are so exuberantly diverse and yet so little understood.

Even a handful of forest litter may contain hundreds of species, including dozens of tiny arthropods of bizarre form and from unusual groups (e.g. proturans, pauropods, palpigrades). With increasing recognition of the importance of soil animals to soil health, there is a growing need for ecologists to identify organisms beyond the traditional, but taxonomically uninformative, size categories of micro-, meso-, and macrofauna. General keys to soil fauna are rare, however, making the ecologist's task a daunting one. This CD's richly illustrated keys to the mites and other microarthropods that dominate soil faunas will be an invaluable tool for researchers, teachers and students interested in understanding the bustling communities beneath our feet.

Mites in Soil includes five LucID interactive keys to soil animals. Although most of the animals illustrated are from Australia, non-Australian taxa have been included so that the keys can be used anywhere in the world to identify classes of soil arthropods; orders of arachnids; orders, suborders and cohorts of mites; and families of soil-inhabiting mites (except oribatids). Each of the keys is lavishly illustrated with original line drawings, photographs, and superb scanning-electron micrographs.

As well as images, each taxon is characterised by a written diagnosis and notes on ecology, behaviour, distribution and important literature. The preface to the CD includes an overview to collecting and mounting mites and other soil microarthropods. All keys allow the user to start anywhere in the list of characters when keying a specimen. This is one of the strongest advantages of interactive keys, as it removes the frustration of dead-end couplets. For example, with the traditional dichotomous key if the first couplet was "eyes: present or absent" and your animal lacked a head, you were stuck. With LucID interactive keys, you can start your identification using any region of your specimen. The other strong point of this software is the convenience of hyperlinked text, which allows one to instantly move from written descriptions of animals or their characters to images of the animal or structure. When the authors began the long process of designing and illustrating these keys, they were still hesitant about abandoning the good old tradition of dichotomous keys on paper. Now we can't imagine going back to those primitive times. The ease and convenience of these interactive keys should convince even the most recalcitrant ecologist that identifying organisms is fun.

The most general key, and the one most likely to become a fixture in undergraduate classrooms, is "Classes and Orders of Microarthopods in Soil". This key allows the user to identify 31 major taxa of arthropods common in soil, including some leggy non-arthropods such as tardigrades and onychophorans. This key is notable for its excellent images of such rarely illustrated taxa as Pauropoda, Symphyla, Palpigradi and Schizomida.

It is not intended as a replacement for the LucID interactive key to insects, however, and identifies insects only to class. The other four keys are devoted to the authors' passion - mites. Soil mites from almost anywhere in the world can be keyed to family, with the few families excluded from the keys diagnosed in introductory notes. The most general of these keys, "Orders, Suborders and Cohorts", allows the user to place any mite into a higher taxon, even mites relatively unlikely to be encountered in soil (e.g. soft ticks). Members of the mite suborder Oribatida can be keyed to cohort, but are not taken further in this CD (oribatids of Australia can be identified to species using the interactive key of Hunt et al. 1998). Members of the other major groups of soil-dwelling mites can be identified using "Families of Parasitiformes in Soil" (46 families of Holothyrida, Ixodida and Mesostigmata), "Families of Prostigmata in Soil" (43 families), and "Endeostigmata and Sphaerolichida" (12 families). These three family level keys include detailed written diagnoses, how to distinguish each family from 'look-alike' taxa, discussions of ecology and behaviour, important literature, and lists of genera known from Australia (these can be updated by clicking on the hyperlink to Bruce Halliday's Acarina group loaded in the Australian Faunal Directory at http://www.environment.gov.au/biodiversity/abrs/online-resources/fauna/afd/ACARINA/tree.html

These five keys should be installed on the computers of anyone interested in soil ecology, mites, or arthropods in general. We hope that they will help ecologists to further understand the pedobiological world, and seduce students into the fascinating field of acarology.

References:

The Mites in Soil CD is available from:

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