It can just be a red back spider...
Have seen a very small spider with 4 white dots and 1 red dot. Not a red back. Ta ~Snaff
yes it means the poisonous spider
a wolf spider. they hurt but are not deadly to humans
A spider.
Redback Spider is indigenous to Australia. It is a venomous spider.
a red back.
red back spider
A black widow spider is black with a red mark on it's abdomen; this might or might not be what you meant. The black widow sometimes has a red mark on her back, as well. The red backed spider of Australia, a relative of the black widow, has an orange red mark on the back.
a spider.
red back
Arachnic
The distinctive feature of a red spider with a yellow back is its unique coloration, which sets it apart from other spiders.