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TaxonomyBrowseInfoImagesLinksBooksData
Photo#500074
Loxosceles from west bank of Mississippi, metro New Orleans - Loxosceles rufescens - female

Loxosceles from west bank of Mississippi, metro New Orleans - Loxosceles rufescens - Female
Belle Chasse, Tulane Hebert Center, Plaquemines Parish, Louisiana, USA
March 21, 2011
Size: 9mm
Found this in a nearly abandoned warehouse space, while shifting old equipment and wooden palettes. I'm very excited, both because this is my first recluse, and because Dr. Carlson and I have been trying to establish whether recluse spiders are endemic to southeastern Louisiana, or only present in the context of crates, lumber, etc. originating from other regions.

Images of this individual: tag all
Loxosceles from west bank of Mississippi, metro New Orleans - Loxosceles rufescens - female Loxosceles from west bank of Mississippi, metro New Orleans - Loxosceles rufescens - female Loxosceles from west bank of Mississippi, metro New Orleans - Loxosceles rufescens - female Loxosceles from west bank of Mississippi, metro New Orleans - Loxosceles rufescens - female Loxosceles from west bank of Mississippi, metro New Orleans - Loxosceles rufescens - female

Medical significance
Not sure if this article was posted:

""Loxosceles rufescens apparently has not been associated with cases of human loxoscelism, but in experiments done on mice and rabbits, the venom of L. rufescens has been found to have effects similar to those of Loxosceles reclusa (Smith and Micks, 1968; Shulov et al., 1962)""

https://kb.osu.edu/dspace/bitstream/handle/1811/5532/V70N02_128a.pdf;jsessionid=949E45B5F1F02905B1C9A2B3DBF1E222?sequence=1

 
Thanks Brian
I added that info to the guide page.

Moved
Moved from Recluse Spiders.

Known issue
I realize that the habitat where I found this spider doesn't resolve our question about endemism. Nevertheless, my instinct is that the warehouse (old naval munitions bunker) is defunct enough that if recluses established from shipping containers, it had to have been many generations ago.

 
Range
Do you think we can move this to reclusa based on range?

 
New info
Just looked at Gertsch (1958) which has a distribution map with a confirmed specimen of L. rufescens from New Orleans.

 
Still more new info!
Ok, I've inexpertly eviscerated the abdomen from the dorsal side, and managed not to destroy the spermathecae. It is definitely L. rufescens. I used this paper by Al Greene which has great comparison photos.

My scope with photo capability is at school, so I won't be able to post the spermathecae until later.

 
I've posted an amateurish pho
I've posted an amateurish photo of the amateurishly slidemounted spermathecae.

 
..
Thanks for that paper! I've added the link to the BG Loxosceles genus info page. The date on the paper is 1983.

 
Thanks, good catch.
I can't seem to edit any but my most recent comment, so I can't fix the date up there. Not sure how I missed that, I think the paper I was originally searching for was Gertsch,1958, and I found that one instead. Oh, internet.

If you don't already have it, you may also want to add the Al Greene 2009 paper I linked to above, with detailed descriptions and photos for distinguishing L. reclusa from L. rufescens.

 
Thanks. I've added the Green
Thanks. I've added the Greene paper to the L. rufescens info page.

This has been a good Loxosceles day for BugGuide!

 
Loxosceles rufescens
Very cool, I didn't think we'd ever see one of those.

 
Probably
I'm almost certain that you're right. My only reservation, which you may have some insight about, is that I don't presently know how to tell the brown from the Mediterranean recluse. I know the latter is invading, and is reported to be in the Gulf states.

About a year ago, Rick Vetter sent me some literature with details on how to distinguish the Loxosceles. This is my first actual specimen, so I'm planning to preserve it and do a genital dissection, both to be absolutely sure on the ID, and also so I can learn how to do it.

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