I want to see the Punnet Square for a Killer Bee

[SteveySingle]

I understand that Spider x Pastel=Bumblebee, and that Bumblebee x Pastel=1/8 Killerbee...Can anyone show me the punnet squares leading up to the Killer bee? PLEASE!!! It's driving me crazy. I've drawn umteen squares and can't figure out how you get 1/8 Killerbee.

I used the Geneteics Wizard but it doesn't show me the Genotypes for the animals NOR do I understand how to write Dom, Co-Dom. I do understand recessive...