AAussttrraallaassiianan AArachnachnoollogyogy Price$3 Number7r773 ISSN0811-3696 JanuAparrily2006007 Newsletterof NewsletteroftheAustralasianArachnologicalSociety Australasian Arachnology No. 77 Page 2 THE AUSTRALASIAN ARTICLES ARACHNOLOGICAL SOCIETY The newsletter depends on your contributions! We encourage articles on a We aim to promote interest in the range of topics including current research ecology, behaviour and taxonomy of activities, student projects, upcoming arachnids of the Australasian region. events or behavioural observations. MEMBERSHIP Please send articles to the editor: Membership is open to amateurs, Volker Framenau students and professionals, and is Department of Terrestrial Invertebrates managed by our Administrator: Western Australian Museum Locked Bag 49 Richard J. Faulder Welshpool, W.A. 6986, Australia. Agricultural Institute Yanco, New South Wales 2703. [email protected] Australia Format: i) typed or legibly printed on A4 email : [email protected] paper or ii) as text or MS Word file on CD, 3½ floppy disk, or via email. Membership fees in Australian dollars (per 4 issues): LIBRARY The AAS has a large number of *discount personal institutional reference books, scientific journals and Australia $8 $10 $12 papers available for loan or as NZ / Asia $10 $12 $14 photocopies, for those members who do elsewhere $12 $14 $16 not have access to a scientific library. There is no agency discount. Professional members are encouraged to All postage is by airmail. send in their arachnological reprints. *Discount rates apply to unemployed, pensioners and students (please provide proof of status). Contact our librarian: Cheques are payable in Australian Jean-Claude Herremans dollars to “Australasian Arachnological PO Box 291 Society”. Any number of issues can be paid Manly, New South Wales 1655. for in advance. Receipts issued on request. Australia Members will receive a PDF-version of email: [email protected] Australasian Arachnology. (hardcopies for long-standing individual members, libraries and societies in exchange). Members will COVER ILLUSTRATION: be notified by mail and email when their Male Dolomedes sp. from Victoria. subscription has expired. By Peter Flagstaff Previous issues of the newsletter are available at www.australasian- arachnology.org/newsletter/issues. Australasian Arachnology No. 77 Page 3 EDITORIAL Lynne Forster 17 King St Sandy Bay, Tas 7005 You could easily call this new issue of Australia Australasian Arachnology a special ‘mite [email protected] edition. Putting this newsletter together, I learned a lot about mites, and this is what Bruce Halliday, the authors of our feature Change of Address article apparently had in mind. Thanks Bruce, for this great introduction to mite Karen Edward systematics and biology! I will upload this School of Animal Biology article onto our website soon to make it University of Western Australia available for a wider audience Crawley, WA 6009 (www.australasian-arachnology.org). Australia [email protected] I have not received any articles for the next issue, so please sharpen your pencils and Sydney Jordan send some articles for Australasian 21 Undara Ave Arachnology 78 which is scheduled for Buddina, Qld 4575 release in September. Australia [email protected] I have not quite packed my bags yet for Brazil, but I am looking forward to catching ---------------------------- up with many of our readers at this year’s th 17 International Congress of Arachnology LIBRARY in São Pedro UPDATE (http://www.ib.usp.br/~ricrocha/ISA17/ISA1 7.htm). Our librarian Jean-Claude Herremans received reprints of publications from Cheers, Volker Helen Smith, Wilson Lourenco, and Herb Levi (via Laura Leipensperger). Thanks a lot to Helen, Wilson and Herb! MEMBERSHIP All our members should consider UPDATES donating reprints of their publications to New Members our library, which is an important source of information for our members without Tenille Nielson access to a professional library! 39 Gregory Terrace I will include an updated list of our Kuranda, Qld 4881 library holdings in one of the next Australia newsletters and will hopefully be able to [email protected] upload this list onto our website at some stage as well. Australasian Arachnology No. 77 Page 4 than those devoted to arachnology. This Mites are arachnids too is a reflection of the fact that mites have much in common with insects, especially Bruce Halliday, CSIRO Entomology, as pests of cultivated plants and crops. GPO Box 1700, Canberra ACT 2601, The purpose of this general article is to [email protected] make mites more accessible to arachnologists who do not have specialist Introduction knowledge of acarology. Almost all arachnids are predators. The only group of arachnids that has managed Classification of the Acari to break out of the predatory habit on a large scale is the mites, which have Mites are the smallest arachnids in terms diversified into an extraordinary range of of body size (although the biggest mites niches. Many are still predatory, but there are bigger than the smallest spiders). are also thousands of species of plant Adults of most species of mites are in the feeders, fungivores, saprophytes, pollen range 300–800 micrometres in body and nectar feeders, microbial filter length. Mites are also distinguished from feeders, and internal and external other arachnids by the complete absence parasites on a wide range of vertebrates of body segmentation, and by the and invertebrates. Others have a complex fundamental organisation of the body. life cycle, in which parasitism and There is no division of the body into predation occur at different life stages cephalothorax and abdomen. Instead, the within a species, and others are mouthparts and associated sensory omnivorous. Mites occur in soil and structures form a discrete anterior decomposing organic matter, in fresh structure known as the gnathosoma. All water and sea water, high in the air, deep the rest of the animal's anatomical in the oceans, on and in the bodies of structures, including leg bases, central other animals, and on plants of all kinds. nervous system, ocelli when present, and This ecological diversity has been reproductive and digestive systems, are accompanied by a bewildering degree of all fused into a single unsegmented body morphological diversity. Their called the opisthosoma. diversification has in turn been reinforced Many systems of higher classi- by their small body size, which allows fication have been used for the mites, them to occupy minute spaces, and and many different names have been makes it necessary to use specialised used for the higher taxa of mites at all techniques for their observation and levels. In the most modern classification, taxonomic study. All of these factors the mites are placed in the class Acari, conspire to create an artificial division within which there are two superorders. between acarologists and other The superorder Parasitiformes includes arachnologists, to the extent that mites order Opilioacarida, order Holothyrida, have their own literature, their own order Ixodida, and order Mesostigmata. anatomical terminology, and their own The superorder Acariformes includes national and international conferences. order Trombidiformes and order One of the outcomes of this division is Sarcoptiformes (Walter 2006; Krantz and that research papers on mites are more Walter 2007). likely to be found in entomology journals Australasian Arachnology No. 77 Page 5 The order Opilioacarida includes a Australia, all in the family Allothyridae single family of large mites (≥ 1 mm) that (van der Hammen 1983), but many other have many character states that are undescribed species have been collected considered to be ancestral (Krantz 1978). and await study. They are widespread but rare in semi-arid There are about 80 known species of climates, where they are found under stones. An unidentified species has been ticks, order Ixodida, in Australia (Roberts collected in Kakadu National Park, where 1970; Keirans et al. 1994, 1996). They are it feeds on mites and insects, as well as all blood-feeding parasites of mammals, fungal hyphae and pollen (Walter and reptiles and birds, and are characterised Proctor 1998). by mouthparts with a large number of backward-directed hooks that are inserted into the host for feeding. The best known Australian species is the paralysis tick Ixodes holocyclus, which can be dangerous to the health of humans and dogs (Anonymous 2003). The order Mesostigmata (e.g. Fig. 1) includes about 80 families of relatively large mites with adult body lengths in the range 300–3000 mm. They are characterised by a series of leathery sclerotised plates that cover the body, and by a pair of laterally-placed stigmata, which are the external openings of the tracheal system. Most are predatory, while a few also feed on pollen and nectar. They occur in a wide range of habitats, including soil and litter, but are also Fig. 1: Species of Asca (Mesostigmata: abundant in dung, carrion, compost, and Ascidae) are recognised by the pair of in the nests of vertebrates. Many are prominent horns or protuberances on beneficial, contributing to the control of the posterior margin of the body. insect and mite pests. Notable among About 80 species occur in leaf litter these is the arboreal family Phytoseiidae, and moss world-wide, where they prey which are widely used in the control of on mites, insect eggs and larvae, and spider mites that damage crop plants nematodes (Gerson et