When is a queen a queen and whe is she a worker.

Is it true that in the laboratory, all larvae fed exclusively on royal jelly turn out to be workers if so there must be something else that they are not fed that produces queens so could it be p-coumaric acid.
http://advances.sciencemag.org/conte.../e1500795.full

Interesting to a point but pretty abstract.

Personally as long as my grafts turn into quality queens that is enough for me.

PH