BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 83 
queen with spotted brood were interchanged, the eggs from the first 
queen showed an increase in brood mortality when reared in the 
other colony, and vice versa. 
The need of winter pollen reserves for maintaining- spring brood 
rearing was brought out in studies at Laramie, Wyo., which showed 
that pollen consumption occurred throughout the winter in colonies 
with both abundant and negligible pollen reserves but was considera- 
bly greater during winter and increased during March and April in 
colonies with abundant pollen. In colonies with negligible reserves 
pollen consumption was less in March and April. Abundant pollen 
reserves are essential if colony population and vitality are to be at 
a maximum at the beginning of the active season. 
Tests on methods of giving colonies additional pollen showed that 
mixing it in honey or sirup is of little use, since the proventriculus 
of the bee acts to separate the pollen before the bees can give it 
to the brood. The tests showed that no brood was reared beyond 
the larval stage when pollen was given this way exclusively although 
egg laying was stimulated. 
In a study on pollen substitutes, pollenless colonies responded to 
being given soybean flour by rearing brood for 10 to 14 days, after 
which they no longer seemed able to mature their brood. Colonies 
with negligible amounts of pollen responded to the flour by rearing 
brood normally for at least 4 to 5 weeks. Colonies receiving soybean 
flour supplemented by either 25 or 50 percent of pollen gave a brood- 
rearing response equal to that of colonies fed pollen exclusively. 
Pollen traps maintained in four California beekeeping areas yielded 
from 33 to 40 pounds per colony during the year. The daily produc- 
tion varied with the season, forming curves similar to the brood- 
rearing curves for the areas. As much as one-half pound per day, rep- 
resenting 15,000 loads of pollen, was obtained by a colony during the 
height of fruit bloom. This shows the great pollenizing value of 
strong colonies in fruit pollination. 
In cooperation with the University of California pollens gathered by 
bees from 34 different plant sources were analyzed. A wide variation 
was found in protein and mineral content, as shown by the following 
summary : Protein, 7 to 35 percent; calcium, 0.3 to 1.18; magnesium, 
0.06 to 0~35 ; phosphorus, 0.11 to 0.81 ; iron, 0.0006 to 0.0071 ; and potas- 
sium, 0.33 to 1.14 percent. 
In studies made in cooperation with the Oregon Agricultural Ex- 
periment Station nectar from yellow sweetclover was found to contain 
more sugar than did that from white sweetclover. In the Imperial 
Valley of California the quantity of sugar in the nectar of alfalfa 
was greater for plants grown on dry soils than for those grown on 
wet soils. In the San Joaquin Valley the nectar secreted by the extra- 
floral nectaries of cotton was richer than that secreted by the floral 
nectaries. 
The terms of the cooperative agreement under which the Bureau's 
bee culture sublaboratory was established at Madison, Wis., provide 
that the Bureau take over practically all the beekeeping work in the 
State. Operation of the Miller Memorial Beekeeping Library is 
thus included. With the cooperation of the University of Wisconsin, 
the collection has been classified by subjects. Cataloging will be done 
at a future date. 
