From Veto-Pharma (maker of Apivar):
"There are no counter-indications to the use of Apivar in the presence of queen cells, or non-mated young queens. The use of Apivar is safe and the product was developed with the primary objective of not harming the colony, or its constituents. For beekeepers rearing queens, it is recommended that colonies be treated prior to commencement of queen rearing activities, and strips be removed before starting the production of queens, in the absence of specific data concerning Apivar use while rearing queens."
"There are no counter-indications to the use of Apivar in the presence of queen cells, or non-mated young queens. The use of Apivar is safe and the product was developed with the primary objective of not harming the colony, or its constituents. For beekeepers rearing queens, it is recommended that colonies be treated prior to commencement of queen rearing activities, and strips be removed before starting the production of queens, in the absence of specific data concerning Apivar use while rearing queens."