Reptile & Amphibian Forums

I am very confused as to species identification and the ranges of the 3 BW species. So far I have been unable to find a clear idea of where the boundary lines are within Oklahoma. Can anyone point me to any source of range maps, species by county, or any similar info?

I have had a mature BW female for just over a year. All along I have assumed her to be Western based on the shape of the hourglass and shape/color of eggsacs, and the location found. Only tonight I read that the Southern usually has the extra red spot at the back of the abdomen- and discovered mine has this. Is this def distinctive of the Southern, or might Westerns also have this? She was collected in Garfield Co, northwestern Ok.

A second female collected from this same area earlier this summer seems to have all the characteristics of the Western species. Although she does still have some red stripe on the upper abdomen, it has faded with both molts since capture, and may well disappear completely with the next (last?) one.

A third individual I collected only yesterday from Alfalfa Co, a bit more NW than the others, was found with eggsac so must be mature (?), has no markings on the upper side of the abdomen, but has a def INcomplete hourglass a la the descriptions for the Northern variety (which I thought was not found that far west.

Basically then, I am very confused as to species identification and specific ranges for the BW species. If anyone could be a bit more definite on species id characteristics and/or ranges of the 3 BW species within Ok or surrounding states I'd be most grateful.

bill

These websites should help you determine which species you have. The first listed shows the typical differences in the hourglass marking, the second and third have distribution information. It appears that both L.mactans and L. variolus are in your state, so you may use the info inthe first site to get an idea of which. Also, the variolus often has white and/ or red spots on the top of it's abdomen. If you're still unsure, I'll find some more resources fo you to look at.

http://kaston.transy.edu/widow.html

http://members.tripod.com/~LouCaru/index-13.html

http://www.hobospider.org/

Thanks! These have been helpful, but I'd appreciate any further refs you may have concerning species id and distribution, esp within Oklahoma.

Some specific questions I'm trying to clear up are...

1. Some refs state that L. mactans has a second red spot posterior to the hourglass. I am wondering, it this ALWAYS the case with the Southern species? Is it possible for any of the other species to have this marking, or is it a definite indicator of L. mactans?

2. I have a mature female from NW Oklahoma (Alfalfa Co) with no markings on top of abdomen, but with clearly separated hourglass. L. hesperus?

Thanks for your time.

bill

The thing with widows is you can't say "always" about most aspects of their coloration, their appearances, even within ONE widow species, are quite variable. Brown widows, for instance, can be nearly black, nearly white, or anywhere in the middle. I have even heard of black widows with blue hourglasses. So you really can't say "always". However, you can say that different species have tendencies to one or more features, and it is a tendency in L. mactans to have a dot posterior to the hourglass, or on the topside of the abdomen, in line with the spinnerets. So that one is MOST LIKELY an L. mactans.

On the widow with the divided hourglass, would you describe the two halves as spots or divided triangles, and how large is the spider?

http://www.cviewmedia.com/Articles/AM01_WidowSpiders.html

http://members.aol.com/TheWyvernsLair/WidowSpiders/

http://www.hobospider.org/

The Widow with the divided hourglass is nearly, but not quite, the size of the mature female we suspect to be L. mactans. I assume she too is mature in that I found her with 2 eggsacs (which were left undusturbed).

I'd say the anterior half of the divided hourglass is a triangle, the back one looks more irregular.