-21- 
none were found among several thousand drones. They can be recognized 
and avoided if the breeder queen is introduced to a colony of bees of a 
distinguishable color. For example, if a queen of a yellow strain is 
introduced to bees of a black strain, her sons and daughters will be 
yellow and the sons of worker bees will be blaok. 
If a selected breeder queen is supported entirely by her own worker 
daughters, it is not so important to guard against the off-type individuals, 
because all descend from the breeder queen and her mate, and therefore repre- 
sent only the desired germ plasm. Often, however, it is unpractical to 
wait for a queen to produce her own supporting population. 
The other types of undesirable individuals, queens reared from \mfer- 
tilized eggs of either queen or worker, are called impatemate because they 
have no male parent. These queens are quite common in some races. Among 
Cape bees of South Africa laying workers develop readily and produce female 
offspring in abundeince when the hive becomes queenless (Jack _1 ) • In other 
races they have been considered to be rare or not to occur at all, but 
Mackensen (_3) has proved their occurrence in three American strains of bees 
representing the Caucasian and Italian races. He found female progeny in 
the brood of 21 out of 50 virgin queens tested. Of the larvae grafted 
from one queen producing a high percentage of female offspring, 0*85 per 
cent developed into queens. Impaternate females also occur in the related 
insect Habrobracon juglandis Ashm., and Speicher (_8) has presented evidence 
that they develop from diploid eggs which arise from patches of tetraploid 
tissue in the ovaries. 
The frequency with which impaternate daughter queens of laying workers 
are likely to be encountered in rearing queens by the usual methods has 
not been determined. If the percentage of impatemate females developing 
from unfertilized eggs of queens. (0.85 per cent) can also be taken as the 
percentage of laying worker eggs that develop into females and the rate 
of occurrence of off-type drones (0«26 per cent) is taken as the percentage 
of laying worker eggs in the hive, the expected rate of occurrence of 
queens of this type csui be calculated to be 0.000022 per cent, or 1 in 
4.5 million. Obviously they are so infrequent that precautions need not 
be taken to avoid them. If it should be desirable, the method described 
for off-type drones could be used, 
Impaternate queens developing from eggs of the breeder queen inherit 
only from her. In ordinary breeding work there is no way of recognizing 
and avoiding them* They probably do not occur among the larvae grafted at 
all because fertilization would lead to triploidy and probably death, and 
the larvae ordinarily used for grafting develop from fertilized eggs. 
CARE OF QUEENS 
To provide the most natural conditions queens are not kept in nursery 
cages prior to insemination, as recommended by some workers on artificial 
insemination, but introduced as cells and maintained in nuclei until they 
begin laying* Excluders are placed, over the hive entrances to prevent the 
loss of queens by mating flights. As soon as possible after emergence, 
