I have not noticed a difference in brood rearing in the presence of apistan
one way or the other. It is an interesting question however because in
Alaska our season is so short we cannot afford any mistakes,one or two
weeks is the difference between a good year and a bad one. Our bees are
shiped in from California in 4 pound boxes some ship in 3 pound. The
supplier ships an apistan strip in the  box and we recieve an inspection
certification. I asked what we should do with the apistan strip and they
said put it in the hive  but when we go up with the next super take it out.
Because you asked I dont know it we would be better with it or without it.
 
Jerry Fries