I’m from Australia and I always thought it was on the top. Turns out our black widow, affectionately known as a redback, has the marking on top. Not sure if the two are actually related, though.
Yes, they are all in the Latrodectus family, all have venom containing the neurotoxin latrotoxin, which causes latrodectism (pain, vomiting, muscle rigidity, sweating).
Australian Redbacks are Latrodectus hasseltii:
New Zealand Katipo are Latrodectus katipo:
Western Black Widows are Latrodectus hesperus:
Southern Black Widows are Latrodectus mactans:
Female:
Male:
Northern Black Widows are Latrodectus variolus:
European Black Widows are Latrodectus tredecimguttatus:
South American Black Widows are Latrodectus corallinus:
I’m from Australia and I always thought it was on the top. Turns out our black widow, affectionately known as a redback, has the marking on top. Not sure if the two are actually related, though.
Yes, they are all in the Latrodectus family, all have venom containing the neurotoxin latrotoxin, which causes latrodectism (pain, vomiting, muscle rigidity, sweating).
Australian Redbacks are Latrodectus hasseltii:
New Zealand Katipo are Latrodectus katipo:
Western Black Widows are Latrodectus hesperus:
Southern Black Widows are Latrodectus mactans:
Female:
Male:
Northern Black Widows are Latrodectus variolus:
European Black Widows are Latrodectus tredecimguttatus:
South American Black Widows are Latrodectus corallinus:
https://en.wikipedia.org/wiki/Latrodectus
Thank you for the well sourced response.
I used to be in a black widow-free area but it seems that European “13 spots” one is now starting to show up here.
Probably not good news.