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Black Widow - Latrodectus mactans - female

Black Widow - Latrodectus mactans - Female
Powhatan County, Virginia, USA
July 27, 2005
Size: Body is 7mm long
A specimen from my collection
Found in web amongst fallen branches.
Identified by Christopher Hunt and Eric R. Eaton.

Latrodectus mactans
Thanks guys!

Yep, that's a female Southern Black Widow...
but it appears she isn't doing too well. She has seen better days. ;)

[Whether she is a juvenile or not, hard to really tell from this picture; she could be fairly young based on the size of the debris around her. Her body measurement might be a better indicator.]

Family: Theridiidae
Genus: Latrodectus
Species: L. Mactan (Southern Black Widow) since the hourglass is complete (no spaces between the triangles).

(L. Variolus (Northern Black Widow) is in Virginia also, but its hourglass is not complete; the triangles of the hourglass do not touch.)

Hope this helps...

I agree.
Southern black widow, but it is Latrodectus mactanS, with an "s" on the end. There is much variation in the extent of the red markings, both individually, and with age, younger individuals having extensive red (and/or white) markings. Black widows in fact emerge from the egg sac WHITE. Males retain much of the paler markings, as they mature faster than females.

L. Mactans
Thank you Eric! I forgot the "s". Still learning to identify and spell the names correctly... :)

Eric: Is the variation in the hourglass (connected or broken) a good (correct) way to ID a southern vs. a northern black widow? Thanks.

Hourglass mark.
I am pretty certain that the northern widow ALWAYS has a broken hourglass, but I've seen western widows that had a broken hourglass marking, so I don't think the reverse statement is true:-) Northern widows are generally smaller, and often, if not always, marked with red lines on the dorsum of the abdomen.

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