Sunday, 14 September 2008

Garden Orb Weaver Spider

.....Eriophora pustulosa

This spider was found on my Vegetable garden fence last Wednesday evening. It is, I believe, Eriophora pustulosa, the Garden Orb Weaver. The species is very variable in colour and pattern as it takes on the colour of it's surrounding. It ranges from yellowish right through to black.

The USQ's Find a Spider site says, the "presence of two projections (tubercles) on the front upper surfaces of the abdomen and a row of three near its pointed end are characteristic of this species." These can be seen best in photo #1. Below the three posterior tubercles are another two vertically aligned tubercles so if you were to view it from behind all five projections would form a letter T. (see diagram #5) It also has a dark quadrilateral area on the ventral surface which is surrounded by a white margin as can be seen in photo #4.

Female body length is 7 - 15mm and males 7 - 8 mm.

Note: older texts refer to this species as Acroaspis tuberculifera or Araneus pustulosus




#1. Garden Orb Weaver Spider - Eriophora pustulosa


#2. Garden Orb Weaver Spider - Eriophora pustulosa


#3. Garden Orb Weaver Spider - Eriophora pustulosa


#4. Garden Orb Weaver Spider - Eriophora pustulosa


#5. Dorsal view of abdomen showing general position of the tubercles



References:
Hickman V.V. - 1967 - Some Common Spiders of Tasmania - Tasmanian Museum and Art Gallery.
University of Queensland Find a Spider Guide - http://www.usq.edu.au/spider/find/spiders/612.htm


9 comments:

  1. Cool! I love the orb weavers. Is this the common species in Tasmania? We get a different 'standard' species, Eriophora biapicata, which is very widespread on the mainland but doesn't occur down your way.

    The Royal Soc of Vic published a handy little book a few years ago about the spiders and scorps of Vic. It might have some of the Tas species too. Authors: Walker, Yen & Milledge, in case you want to check it out.

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  2. Nice post.
    These are not as scary as the Huntsman (I think it is the eyes, and the fact that the Huntsmen come inside the house). That is, unless one happens to walk right through a web, out in the bush. The ones which eat their own webs before dawn, and spin a new web each evening, are more friendly, from that point of view.
    Thorough bit of research, there.
    Denis

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  3. Thanks Snail - It's said to be common throughout Tassie.. Certainly at my place it seems to be.

    Thanks for the tip of the Vic spider book. I'll have to get that.

    Thanks Denis - They're all scary if you ask me but I still love 'em :-)

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  4. I like 'em much bigger. Yours looks very like E. transmarina, the GOW up here, according to Wildlife of TNQ.

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  5. Thanks Tony - You can keep the bigger ones. I'll just look at any photos you get. :-)

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  6. Good on you Mosura, you've confirmed that my spider is also E pustulosa. I just Googled one up on the Morwell National Park site that's very similar in markings to mine.

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  7. Thanks Duncan - That's why I posted it. I was trying to be subtle ;-)

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  8. Great photos, I don't know too much about spiders and enjoyed learning about this one. Are these a poisonous variety? Not sure whether you have any lethal spiders in Tasmania. Sorry if this sounds a bit dense.

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  9. Thanks Denise - poisonous yes but not deadly. We do have a few nasty ones here and a couple of potentially lethal ones.

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