AAuusstrtraallaassiianan AArrachnachnoolloogygy Price $3 Number 73 ISSN 0811-3696 January 2006 Newsletter of Newsletter of the AustralasianArachnologicalSociety Australasian Arachnology No. 73 – January 2006 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 [email protected] Yanco, New South Wales 2703. 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 n photocopies, for those members who do NZ / Asia $10 $12 $14 not have access to a scientific library. elsewher $12 $14 $16 Professional members are encouraged to e send in their arachnological reprints. There is no agency discount. Contact our librarian: All postage is by airmail. *Discount rates apply to unemployed, pensioners Jean-Claude Herremans and students (please provide proof of status). PO Box 291 Cheques are payable in Australian Manly, New South Wales 1655. Australia dollars to “Australasian Arachnological Society”. Any number of issues can be email: [email protected] paid for in advance. Receipts issued on request. COVER PHOTOGRAPH: Status box on the envelope indicates Eriophora pustulosa ♀ (Victoria) the last issue paid for. Volker Framenau Previous issues of the newsletter are available at $2 per issue plus postage. Australasian Arachnology No. 73 – January 2006 Page 3 EDITORIAL MEMBERSHIP UPDATES This issue is a bit late (January instead of December), since the “Invertebrates 2005” meeting in Canberra New Members in December with the Symposium on Australasian Arachnology took up all my attention. It was indeed an exciting Claudia Ludy meeting, with one of the highlights being Obere Hauptstr. 16 D-85354 Freising the informal dinner for everybody not Germany working on animals with 6 legs! Thanks to [email protected] Barry Richardson for organizing this dinner at his local soccer club! You can find all abstracts of the oral and poster Sydney L. Jordan presentations on arachnology from the PhD Student - Zoology meeting in this issue. Stay also tuned for University of New England a conference report in the next issue of Armidale 2351, NSW Australasian Arachnology. Tracey [email protected] Churchill took the opportunity of the meeting to reflect on our society’s history (pages 13). Naturally, thanks to all others ---------------------------------------------- who contributed articles to this issue. Great to see, that there is student activity in arachnology, with two abstracts of theses dealing with spiders (Gaynor THESIS Owens and Matt Bruce). Steve Nunn ABSTRACTS delivers a great natural history account on an Australian theraphosid, however, I couldn’t fit his whole article into this issue Conserving Biodiversity in the and a second part of his contribution will Rangelands: Are Land Systems appear in the next Australasian Effective Surrogates for Spider Arachnology. Assemblages? With the New Year, my research Gaynor Owen focus changes from my beloved wolf spiders to an equally fascinating group, Honours Thesis, Curtin University of orb-weaving spiders of the subfamily Technology, January 2005 Araneinae. You can find some Supervisors: Dr. Karl Brennan, Bruce background information on the Australian Ward Araneinae in this issue. Effective conservation planning requires All the best for 2006, and keep understanding ecological processes as the contributions rolling in! well as the spatial and temporal patterning of biota. Here, environmental Volker surrogates, such as land systems derived Australasian Arachnology No. 73 – January 2006 Page 4 for the pastoral industry, may assist in the divided into areas higher and lower in the design of nature reserves. Previous landscape: Bullimore Dune and Bullimore investigations show support for land Flat. To understand the influence of systems as surrogates for biodiversity in environmental/biotic factors on spider the rangelands. However, few studies assemblages, vegetation species, examining the effectiveness of land vegetation structure and soil properties systems as surrogates consider spiders. were measured. Here I determine if land systems might act as surrogates for spiders and then examine how plant species, vegetation structure and soil might influence spider assemblages. I determine if plants and spiders are patterned more finely than land systems by testing for differences between landforms higher and lower within one land system. Finally, I determine if higher taxonomic levels (families) are effective surrogates for spider species. Fig. 2: Bullimore dune habitat. Significant differences in spider species and family compositions occurred between the Bullimore and Sherwood land systems. Spider assemblages are potentially responding to clear differences in vegetation species, vegetation structure and soil properties. The most important soil property that correlates with spider assemblages was ‘texture size’. Plant species Solanum lasiophyllum (Solanaceae) and Dicrastylis brunnea Fig. 1: Gaynor Owen vacuuming spiders (Lamiaceae) showed a weaker from spinifex (Triodia) in the Sherwood relationship with spider assemblages, land system. while the vegetation structural category ‘bare ground’ showed a stronger Data were collected from Lorna correlation. Spider species composition Glen Station in the rangelands of Western differed significantly between the Australia. To test if there was an overall Bullimore Flat and Bullimore Dune difference in spider assemblages between landforms, however spider family land systems, two different land systems composition did not. This suggests were examined, Sherwood (Fig. 1) and spiders are less sensitive at the family Bullimore (Fig. 2). To assess if spider level than the species level between assemblages differed between landforms, landforms. Differences in spider species the Bullimore land system was further composition between the Bullimore Dune Australasian Arachnology No. 73 – January 2006 Page 5 and Bullimore Flat landforms are The Function and Phylogeny of potentially attributed to the heterogeneity Web Decorations in Orb-web of soil properties, vegetation structure and Spiders vegetation species within the Bullimore land system. Matt Bruce Submitted for the degree of Doctor of Philosophy, Macquarie University, May 2005. Supervisor: Mariella Herberstein The aim of my study was to illuminate the function, variability (ontogenetic and phylogenetic), spectral reflectance and phylogeny of the curious silk structures termed web decorations or stabilimenta. Fig. 3: The shuttlecock wolf spider, These structures have attracted the attention of scientists for more than 100 Mainosa longipes (L. Koch), in its burrow. years. Yet, it has been only in the past 15 These results show that years that the various functions proposed environmental surrogates, such as land for web decorations have been systems, are not able to accurately experimentally tested. Furthermore, represent entire spider species richness during this period the variation in these and diversity in the rangelands of structures, both phylogenetic and Western Australia. Moreover, the higher ontogenetic has become apparent. taxonomic approach is not appropriate in First, I tested the hypothesis that achieving a full understanding of the web decorations increase the foraging heterogeneity and patchiness of the biota within the landscape. The importance of success of ‘Araneus’ eburnus by choosing the appropriate resolution/grain attracting prey to the web. Using field size is discussed. Recommendations for correlations and field manipulations I effective biodiversity monitoring within the showed that decorated webs capture rangelands of Western Australia are more prey per web area than undecorated made. webs. However, this is only the case in undisturbed habitats, perhaps due to ---------------------------------- differences in prey assemblages between undisturbed and disturbed habitats. Whist the UV-reflective nature of web decorations has long been established, their visibility to prey and predators has never been objectively assessed. I used spectrophotometric analyses to show that the decorations of five tested spider species are visible to Australasian Arachnology No. 73 – January 2006 Page 6 honey bees and birds over short and long decorations. My work highlights the distances. Furthermore, the discoid significant ontogenetic variation in decorations of Argiope mascordi may decorating behaviour across three provide some protection against species. Consistent differences in linear arthropod predators as the spiders’ versus cruciate decorating behaviour in abdomen and the decoration silk may be the sympatric Argiope aetherea and A. of a similar colour. However, the picta from convergent