- 18 - 
The bumblebee is one of the earliest of the native bees to 
feed in the spring, but the entire colony, except the queen, perishes 
during the winter. 
In the spring the whole responsibility of rebuilding the colony 
devolves upon the queen. She lays and incubates the eggs, seven to 
sixteen in number , feeds the newly hatched larvae and only after the 
first brood matures can she give her strength entirely to brood rearing. 
By fall the colony may have grown to a size of from one to five hundred 
individuals. Certain of the mining bees, Halictus , which nest in 
certain cliffs, have one or two generations a year. The spring genera- 
tion consists of hibernating, fertilized females which give rise to 
a summer generation. The leaf-cutting bee, Megachile spp., apparently 
has but one generation a year and includes but a small n umber of indi - 
v iduals . The carpenter-bee, Ce ratina doola, has two broods a year v/hich 
are very restricted in numbers. 
These examples are typical of the life history of o ur common 
native species of bees thathave from one to fi v e or six br o od cylces 
a nnu ally, while the number of individuals range from a s c ore to a few 
hundred . Comparing this with the honeybee's record of f rom t welve to 
f ifteen brood cy cles a year, all the descendants of a singl e queen , 
whi ch may reach a hundred thousand bees annuall y, or more, we realize 
the wonderful reproductive powers of this insect. It should also be 
noted that instead of the death of all the workers, the winter's mor- 
tality among honey bees is usually very slight. From five hundred to 
sixty thousand may be present in a single colony at the close of winter 
and two or more brood cycles may be reared in the spring before many of 
the fruit trees bloom. 
Fruit Crops 
trees fail to bear. U.S. Dept. Agr. Leaflet 172, 
ild, H. 
P. 
1939. 
Why fruit 
5 pp. 
pp. 3-4: Self-sterility is very common. It occurs in many 
varieties of apple s, most varieties of pears , probably in all varieties 
of sweet cherries , in most if not all varieties of the native and 
Japanese plums , and in some varieties of European or domestic plu ms 
and prunes . Sour cherries are considered largely self-fertile, al- 
though there is some evidence of partial self-sterility. Most peach 
varieties are self-fertile; the J. H. Hale and June Siberia (Mikado) 
are notable exceptions, as they require cross-pollination . Sterility 
in plums, cherries, and perhaps other fruits may sometimes be due to 
deformed or imperfect pistils. Some grape varieties must be cross- 
pollinated in order to be fruitful. 
There is every conceivable degree of self-sterility, from one 
extreme where no fruit sets without cross-pollination to that where it 
