Kerry,    During the early 1970's, I used to use the Starline hybrid on
occasion in my pollination business.   It became quite standard procedure for
me to allow only the very dark queens that might result from swarming cells
or supercedures to head colonies.    In  quite a number of cases when I chose
the resulting "Italian looking" queen, light yellow in color, there would be
vicious progeny afterwards and a very mean hive.   As to it disappearing, yes
it sometimes did so but rarely did I allow it to continue to exist too long
as I didn't want the "viciousness" to be bred into my other hives.   When
this started to happen with predictability, I changed over to a strain of
bees and have continued to do so instead of using hybrids.    My business has
become again an enjoyable hobby and the predictability of a strain of a
definite race adds to the enjoyment.     The afore-mentioned experience
happened quite some time ago and no doubt the Starline hybrid has changed
considerably since.   Some  hobbyists enjoy them very much.   But in my
opinion you are correct in what you imply in your question, as I witnessed it
often enough.