I find widows in general to be a very alluring and beautiful genus, but there is something else about the more interestingly marked species. I would put L. variolus up there, too, with their occasional white and red stripes.Love me some treds, @dangerforceidle, always happy to see pics of them
This guy sure looks like pictures on the web of a redback. She was found on the plateau in east Tennessee and has a solid red stripe on her back. Thoughts?
In southern California, it is a medeterranian climate just like southwestern Australia. If redbacks were to somehow hatch there it would be likely they would be outcompete by the native and non native animals first off, but the conditions, especially in urban areas might offer a favorable environment and a few could survive. Luckily the chances of this happening are very unlikely, not a ton of people have redbacks as they are somewhat rare still in the USA, and those who do have them are responsible I would hope and wouldn’t allow any escapes.
I'd agree there. I've often wondered about the bridge between new world, old world, and the Lemurian and how, when and where Latro crossed it.
It’s a latrodectus sp. could be mactans or variolus. Quite a beautiful female, and a little bit higher up than I usually see widows. She won’t bother anyone as long as no one sticks their hands in her web. As with all widows they are shy in nature and do have a powerful venom but would rather use it on food. The ‘little spiders’ are actually old molts by the looks of it. If there are other questions or concerns please feel free to post more.
The most powerful (LD50-mice) venom in Latros is in a North American species, L Geometricus. However, this is not the determining factor in the (very rare) need for anti-venin.
The determining factor is always the MMO, Means, Method and Opportunity. The most anti-venin ever prescribed for a patient was in fact an Australian man and a Hasselti was involved. The spider was trapped between his body and the bed and bit effectively multiple times. This is extraordinary and extraordinarily rare. The average Latro bite is usually trivial, described by one expert as a warning nip a dog would give. They will always run and hide if at all possible.
Two Latro bites. The red, recent - L Hasselti, and the bump on my knuckle - L Hesperus, 30 years old. Neither was medically significant.
LD50 values for some of the N.A. Latrodectus species:
Latrodectus geometricus = .43 mg/kg (IV) & .223 mg/kg (IP)
Latrodectus hesperus = .84 mg/kg (IV)
Latrodectus mactans = 1.39 mg/kg (IV) & .90 mg/kg (SC)
Latrodectus bishopi = 2.2 mg/kg (could be IP)
Latrodectus variolus = 1.8 mg/kg (IP)
(Data from @Widowman10 web site: https://sites.google.com/site/widowman10/)
A report I read from the Museum and Art Gallery, Northern Territory, http://www.magnt.net.au/ had the LD-50 of Hasselti at .60-.85 mg/kg. Equivalent to Hesperus.
My understanding is that mactans is the most potent of the North American species and bishopi/geometricus is the least. I’ve heard about geometricus being the most toxic, but they aren’t considered medically significant.
