The female of which poisonous spider has distinctive red marks on its abdomen?

um, redbacks do too

it's a bloody Redback.

Redback spiders here in OZ have redbacks! Hence the name?!

I have an aversion to spiders . It is deep and all consuming

Ralph, Yes, it is a bloody redback! AND they are on the toilet seat, as ol' Slim Dusty sang! 😁

Female redbacks in Oz also. They are a direct cousin of the Black widow

WalksBySelf, the Black widow in US does not have stripe. The Australia Redback does (it is a type of Black Widow). This was not a good question. No Australian would call a Redback a Black Widow spider.