Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Photo#230396
unknown spider - Latrodectus mactans

unknown spider - Latrodectus mactans
Kansas City, Missouri, USA
December 31, 1969

Moved

Moved
Moved from Southern Black Widow. Moved to L. hesperus based on comments here. Widowman noted that "L. hesperus markings are quite distinctive in this stage, just the outside edges of white are left, and these usually disappear with the final molt."

 
Not so fast!
Haha! Not all of these "ID" criteria are black and white (no pun intended based on the picture...).

Even though this spider displays very hesperus-like dorsal markings, it still falls squarely in the range of mactans, and displays very mactans-like leg banding. In a case like this, ideally I would want to see an hourglass shot, and even more ideally, I would love to see this spider in the other stages of it's development.

I would still feel decently comfortable putting this under mactans.

 
Sorry!
Crap, sorry, I misinterpreted that to mean that you were IDing this one as L. hesperus? Confused, ha! I thought you made that comment in direct reference to this specimen.
I would still feel more comfortable omitting range from decisions with these or other Latrodectus, but I'll move this one back to mactans (sorry for all the moving James!), haha. As long as, even with range omitted from the decision, it still looks like mactans.
I've been on a personal mission with these lately, sorry for being so annoying, haha! I'm putting in for a specimen loan from the DMNS later, I'll probably also get some Latrodectus, just to see what I can learn from those that have been ID'd by genitalia. The patterns will be limited in preserved ones, but there's other stuff I can learn about them.

Moved
Moved from Widow Spiders.

based on the not-so-bold dors
based on the not-so-bold dorsal markings, and location, i would say L. mactans.

also of note is the leg banding, not often seen in hesperus.

Moved
Moved from Spiders.

One of the Widows
in the genus Latrodectus

 
Maybe a Northern Black Widow?
Maybe a Northern Black Widow? I was told that between the white spots on the back of the abdomen, is crimson.

 
Immature.
Immature widows start out mostly white, believe it or not. As they age, most female individuals lose the bulk of their bold white and red markings. Males retain markings like this as adults, but this specimen appears to have not reached adulthood.