Male sterile onions?

[Lauren]

Does anyone know of (or know how to find) a list of male sterile onion varieties? We got seeds from onion sets this year and it occurred to me that I have no idea which varieties are male sterile. I don't remember what they were called, but if I see the name in print I'll probably remember. It's a white onion and they matured in early to mid August, so that cuts out some varieties. The skin is white as well, but it's not Texas Sweet or Candy.

I would also be interested in a list of hybrids and what the parents were for each.

[Walt]

Nearly any F1 hybrid onion variety will be male sterile in the F2.  Commercial hybrid onion seed producers have no reason to breed male fertile F1 seed. 
The breeding is done with plants in normal. male fertile, cytoplasm.  Then the best inbred lines are bred into male sterile cytoplasm.