A comparative study of ovarioles number in workers of bees, Apis mellifera L. of 36 backcrosses colonies (Africanized and Italian), and stock, inbred and F1 colonies was carried out. No difference on the number of ovarioles in right and left ovaries of workers from the colonies used was detected. The hybrid bees from F1 generation presented from 2 to 31 ovarioles. The number of ovarioles observed in backcrossed Africanized workers varied from 2 to 56 and from 2 to 117 in the Italian ones. The range observed in these bees may be partially explained by the variability registered in stock colonies (Africanized workers: 2 - 16; Italian workers: 6 - 26) and in F1 colonies (2 - 31).
Insecta; Hymenoptera; Apidae; ovary; hybrid bees
