-25- 
tizations of 10 minutes' duration spaced 1 or 2 days apart will cause 
virgin as well as inseminated queens to begin laying promptly; whereas 
without this treatment few begin earlier than 30 days after emergence. 
Individual matings can be made, but so few sperms (0.87 million) 
reach the spermatheca that most queens stop laying fertilized eggs within 
2 or 3 months* If 2o5 mm.' of semen, taken from several drones, is given, 
sufficient sperms (2.97 million) reach the spermatheca to last a season 
if the queen's laying is restricted by keeping her in a nucleus hive. 
Two inseminations of this size provide sufficient sperm (4,11 million) 
to assure fertilized eggs for a season in a full-size colony. Vvith four 
inseminations of this size almost as many sperms (5.52 million) reach 
the spermatheca as are found in naturally mated queens (5«73 million). 
Sperm numbers are estLniated by dispersing the sperms of the sperma- 
theca or of the seminal vesicles of the drone in a given volume of water, 
counting the number of spenns in a measured sample in a counting-chamber 
slide, and calculating the number in the total volume. 
Queens to be inseminated are introduced as cells and confined to the 
hive by queen excluders. Soon after emergence the virgins ara marked and 
their wings clipped. They are returned to the nucleus immediately after 
insemihation while they are still completely anesthetized. 
V»hen drones are reared from a selected breeder queen, sometimes as 
high as 0.26 per cent of the drones obtained develop from the unfertilized 
eggs of laying workers. These off-type drones can be avoided if the 
breeder queen is first introduced to a colony stocked with worker bees 
having a body color distinct from that of the breeder queen, so that the 
drones produced by the v^orker bees can be recognized and discarded. Virgin 
queens are also known to develop from unfertilized eggs of laying workers, 
but are so rare that they need not be considered seriously by the bee 
breeder. 
Drones can usually be produced by creating conditions similar to 
those existing at swarming tine. Crowding of bees, reducing the laying 
space for the queen, and feeding of sugar sirup and pollen are some of the 
steps often necessary* A sure way to obtain drones is to produce drone- 
laying queens by carbon dioxide treatment. Drones in large numbers are 
best cared for in queenless colonies, confined by queen excluders, vfith 
brood, bees, pollen, and honey added as needed. 
