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RE: Tegenaria agrestis
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Helsdingen, P.J. van
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Apr 27, 2009 00:06 PDT
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The whole story about Tegenaria agrestis being harmfull to humans is a HOAX!
Peter van Helsdingen
P. J. van Helsdingen
European Invertebrate Survey - Nederland
European Invertebrate Survey - International
National Museum of Natural History
Darwinweg 2, 2333 CR Leiden, Netherlands
P.O. Box 9517, 2300 RA Leiden, Netherlands
tel.: (0031) 71 56 87 413 or (0031) 06 51058720
fax: (0031) 71 56 87 456
E-mail: helsd-@nnm.nl
http://www.naturalis.nl/eis
http://www.european-arachnology.org/reports/fauna.shtml
denk aan het milieu - dit mailtje printen is niet altijd nodig
"There is grandeur in this view of life" (Darwin 1859)
-----Oorspronkelijk bericht-----
Van: Greta Binford [mailto:binf-@lclark.edu]
Verzonden: zaterdag 25 april 2009 17:38
Aan: arach-@topica.com
Onderwerp: Re: Tegenaria agrestis
Hello all,
Melissa Gaver is working on Tegenaria agrestis for part of her Ph.D.
work. What I did was a comparative analysis between Pacific Northwest
T. agrestis and European T. agrestis because I thought it was
interesting that there were never any reports of clinical issues
associated with their venoms in Europe. I was curious to know if
there were unique chemicals in the US populations or if I could find
some other difference between the two (habitat, proximity to humans,
etc). I did not find evidence of chemical difference between US and
European populations, but I did find striking differences between
sexes within populations. I also did not find any differences in
insecticidal potency between the populations. This is all published
in a manuscript that is available at my website http://www.lclark.edu/
~binford/ . As a side project for that work I sent spiders and venoms
to Hernan Gomez who injected venom from European and N. American T.
agrestis males and females into rabbits (the same strain used by
Darwin Vest). We also tried to get the spiders to bite rabbits. We
could not get the spiders to bite, even by harassing them and
pressing their chelicerae against shaved rabbits. Furthermore all of
the injections produced nothing more than a red bump. We did not
publish this because sample sizes were low. As far as I know that's
the current state of understanding.
Discover magazine wrote a nice article about this issue in 2005 or
2006. I don't think the story has changed since that article came out.
Greta
On Apr 25, 2009, at 8:06 AM, Chuck Kristensen wrote:
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Hi Zachary,
I have not heard of any definitive results and I do not know of anyone
who is looking or is even interesed in looking at this seriously
now. As
I recall, Darwin was only able to get a little necrosis in a couple
New
Zealand white rabbits (but not in a few other animals), Greta Binford
did not detect Loxosceles-style sphingomyelinase D in T. agrestis and
another bioassay only came up with very weak inflammatory activity.
This could be a difficult project. Even if the activity does exist, it
might take years to find a validate a suitable animal model and/or
cell-based assay and the project could be even more complicated if the
toxin(s) is unstable or if they only produced by one gender at a
certain
age or under specific enviromental conditions.
We maintained a colony of Tegenaria agrestis from Salt Lake City
several
years ago, but were not able to generate much interest in the venom
and
eventually let the colony go senile and die off of old age without
breeding.
We would like to start up another colony sometime soon and have been
asking for live specimens from collectors. Their venom isn't even
available for research now.
Very best,
Chuck
Spider Pharm
http://www.spiderpharm.com
outlande-@yahoo.com wrote:
| | Thanks guys,
I myself become overwhelmed with spider identifications this time of
year here in Utah. Every other person thinks their home is
infested with
brown recluse spiders or what not. I had been curious about true
toxicity levels of T. agrestis.
thanks Rick
Zachary J. Valois
Salt Lake City, Utah
Z_Va-@yahoo.com
--- On Fri, 4/24/09, Rick West <rickc-@shaw.ca> wrote:
From: Rick West <rickc-@shaw.ca>
Subject: RE: Tegenaria agrestis
To: arach-@topica.com
Date: Friday, April 24, 2009, 8:34 PM
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Hi Kelly,
I didn't notice your posting on this forum until after it was sent.
Please excuse the
previous typos everyone (corrected below). I suspect Robb's email
was
not noticeable
in the reply. I recommend you contact him directly
at; Robb.B-@gems6.gov.bc.ca
Hope this helps, Rick
From: Rick West [mailto:rickc-@shaw.ca]
Sent: Friday, April 24, 2009 7:09 PM
To: arach-@topica.com
Cc: Robb Bennett (Robb Bennett)
Subject: RE: Tegenaria agrestis
Hi Kelly,
Allow me to refer you to a local authority on T. agrestis - Dr. Robb
Bennett. The majority
of local spiders brought in by paniced arachnophobes aren't even
capable
of penetrating
human skin with their bite. Of those that can, its believed that
bacteria around the mouth
and fang region may be responsible for many of the neucrotic
lesions seen in patients.
These people may be more sensitive to particular bacteria that
enter the
bite site ... if it
was, in fact, caused by a spider at all.
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