Grey Huntsman egg sac – Photo: A Moore
By: Michael Fox
“What is this white thing that looks like a tea bag” Alan asked, leading me to a dead tree beside the Farm Fire Trail through Fox Gully Bushcare.
The “tea bag” is actually an egg sac of a Grey Huntsman Spider Heteropoda immanis.
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Grey Huntsman Heteropoda immanis
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A fearsome looking creature these spiders can inflict a painful but not poisonous bite. Generally timid the females will strongly maternal and will protect egg sac. http://www.arachne.org.au
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Egg capsules – Photo: A. Moore
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Having found the spider eggs Alan explored the dead tree to see what else is living in this unexpected habitat. Macro photography of empty egg capsules show that the tree is also home to shield bugs, probably the Common Gum Tree Shield Bug.
We tend to assume a dead tree, or stag, is only useful for firewood. Alan’s photos show that this “dead” habitat is still alive with species that depend on it for breeding.
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Common Gum Tree Shield Bug
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I have photographed this Common Gum Tree Shield Bug Poecilometis patruelis laying her eggs in 2010.
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Perfectly formed egg capsule lids
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Zooming in even closer we can see that these neat capsules also have perfectly formed lids that pop off as the bugs hatch out. Click on photo to expand and look at bottom right capsule.
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Lacewing eggs – Photo: A. Moore
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Alan was also fascinated by the hundreds of tiny mushrooms growing on the tree. However, when I received Alan’s macro picture I realised these were Lacewing eggs each one mounted on an individual thin stalk.
March 26, 2014 at 6:40 pm
Hello, Michael, Thanks very much for this most recent posting. Very interesting to read about these 3 very different invertebrates. A thank-you also to Alan Moore, for most of the photos.
Reading this has raised 2 queries with me :- 1.. naming of the spider; 2.. any other bugs? Regarding number 2 above, I’m curious to know whether any other Bug (i.e. Hemiptera) species have been found and identified in the Mt. Gravatt Reserve and nearby areas – including Assassin Bugs. As I guess you know, the latter are carnivorous, feeding on various other insects.
Regarding number 1 above – I’ve had several of those small Pocket Wild Guides, published by the Queensland Museum, for just over a year, now – that includes “Spiders of the Greater Brisbane Region”. This book’s chapter on Huntsmen Spiders (family Sparassidae) describes just 4 species, presumably the most common ones. Their names show some discrepancy with the name you’ve given in this posting. In the book, the Brown Huntsman has the zoological name Heteropoda jugulans, while the Grey Huntsman is named Holconia immanis. Since I’ve known for some time that, in the biological sciences at least, different authorities sometimes give differing names to the same organism (and names are also subject to revision and change as further knowledge is gained), I therefore went to the site that you quoted, http://www.arachne.org.au (a site I hadn’t heard of, before), and there clicked on the link to the Checklist of Australian Spiders. This turns out to be a 98-page PDF document! Fortunately, its spider species are listed in alphabetic order, with the family name first, then genus and species names. (However, this Checklist contains no common names for the species, only for the families.) Family Sparassidae begins at the bottom of page 61. In this family, I found the following :- Heteropoda jugulans (L. Koch, 1876), Holconia immanis (L. Koch, 1867). Clearly, these 2 species have kept their zoological names unchanged for some 150 years! I was very interested to see that quite a large number of species in these 2 genera did not receive their official names until the 1990s.
Sometimes it happens that 2 unrelated species end up with the same species-name (though different genus-names). I have seen this happen with plants; whether it has happened in the Animal, Fungi, or Protista Kingdoms I cannot say. However, the above Checklist does not mention a species Heteropoda immanis at all.
I’ll leave this discussion with you, to draw your own conclusions. I hope it hasn’t been too boring to any of the people addressed here!
As a final comment – I decided to send this e-mail rather than trying to post a reply/comment on the web-site, since that doesn’t seem to be working properly at present, for reasons unknown to me.
Until another time, cheers, Noel Hart.
March 26, 2014 at 7:20 pm
Thanks Noel.
It will take me a while to digest all your points however I can say that the following bugs are listed in our Flora & Fauna of Mt Gravatt Conservation Reserve. Including the Common Assassin Bug.
Coreidae Bug Mictis profana Crusader Bug
Margarodidae Bug Monophlebulus sp. Snow Ball Mealy Bug
Pentatomidae Bug Poecilometis patruelis Common Gum Tree Shield Bug
Reduviidae Bug Pristhesancus plagipennis Common Assassin Bug
Michael Fox