Virgin Daughters of Hygienic Breeder Queens
Virgin daughters are also reared from the same hygienic breeder colonies. They will be mailed to beekeepers when they are a few days old to introduce into a queenless colony and then to mate when aged about one week. Although virgin queens less often sold by queen rearers, we plan to do so to increase the supply of hygienic queens. In addition, there are two other potential advantages for a beekeeper: 1) they are cheaper; 2) by mating with local drones the resulting workers will have a combination of local genes from the drones and hygienic genes from the queen.
Yes, you are right, the sentence in bold might be construed to mean that daughters are hygienic but it is worded quite carefully to only infer that they might be.