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Photo#50723
Ant-mimic Spider - Coleosoma acutiventer - male

Ant-mimic Spider - Coleosoma acutiventer - Male
Baton Rouge, Brookhollow Drive, East Baton Rouge Parish, Louisiana, USA
May 5, 2006
Size: body length 2.2 mm.
Spider was found in our carport, repelling down the door of the van. Very black, very shiny creatures are a challenge to photograph!
Gayle

Images of this individual: tag all
Ant-mimic Spider - Coleosoma acutiventer - male Ant-mimic Spider - Coleosoma acutiventer - male Ant-mimic Spider - Coleosoma acutiventer - male Ant-mimic Spider - Coleosoma acutiventer - male Ant-mimic Spider - Coleosoma acutiventer - male Ant-mimic Spider - Coleosoma acutiventer - male Ant-mimic Spider - Coleosoma acutiventer - male Ant-mimic Spider - Coleosoma acutiventer - male Ant-mimic Spider - Coleosoma acutiventer - male

Spider ID
Dr. G. B. Edwards has kindly identified this creature as Coleosoma acutiventer in the family Theridiidae. I find no page for the genus on Bugguide. Would someone please prepare a page?
Thanks
Gayle

 
Hey! We weren't crazy
for suggesting Argyrodes after all. Maybe we really are beginning to learn something. :) Big Thanks to all you BugGuiders for all that you teach us!

 
Hope
You were right on target on the street, but just a couple of doors off on the address! Maybe there is hope for us too!
Thanks for your interest in our images.
Gayle

See
Tom's image. Looks like Myrmecotypus lineatus.

 
Hi Jeff,
Thanks for looking at our images. I have some reservations about this being Myrmecotypus lineatus. I note that Tom's specimen is listed as 6.5 mm., while ours is 2.2 mm. They both appear to be adult males. Also the ratio of the length of the carapace to the abdomen on Tom's is about 50-50, which is in agreement with the drawing here, (1), while ours is about 40-60. It sure does appears to belong in Myrmecotypus.
I preserved the specimen and tried to check the genitalia, but 40 power on my stereo microscope was not up to the task. I have an old monocular microscope stored away somewhere, that may do the job if I can find it. We appreciate your fine images and comments on BugGuide.
Gayle

 
Hi
There is considerable variation in the size of sexually mature spiders with many species. Adult male Phidippus audax for example, range from a BL of 4mm to 15mm.

Carapace to abdomen is impractical because abdomen length is too variable. Your specimen may be old and shrivled from lack of food. Tom's may have molted or consumed prey recently. The drawing you refer to is by no means a standard ratio for the species.

I hope you are able to ID your specimen. If it is not lineatus, I am very curious as to it's identity. Maybe a dwarf spider?
Look forward to more of your close ups; the male O. salticus are my favorites.

 
Thanks Jeff,
In the past, my major identification problems were with the micro moths. The rule with them was: If they look alike, don't believe it until you have done the genitalia! With spiders the rule might be: If they look different, don't believe it until you have done the genitalia! Or painstakingly reared multiple generations as you have done. I am still working on a proper setup to look at and photograph palpi and other details of small spiders so that I can tackle this one.

Thanks for your kind comments on our images.

Gayle

Very nice.
I've never seen one of those spiders up close. Neat shots.

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