BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 
19 
the boll weevil than calcium arsenate, less effective against the cotton 
aphid than nicotine, and less effective against the cotton leaf worm than 
arsenical insecticides. Encouraging results were obtained in experi- 
ments with the bollworm, pink bollworm, thrips, plant bugs, and 
stinkbugs, all of which have been difficult to control. 
BEE CULTURE 
HONEYBEES POLLINATE MANY AGRICULTURAL CROPS 
The benefits from research in bee culture are not confined alone to 
improvement in the production of honey and beeswax. Whatever 
advancements are made in the handling of bees, such as in the control 
of bee diseases, swarming, and other problems facing beekeepers, at 
the same time improve the pollination of important agricultural crops. 
In evaluating research in this field this fact should always be kept in 
mind, inasmuch as the profitable production of about 50 crops rests 
upon the beekeeping industry. Since beekeepers are dependent upon 
honey markets, the role of n'oney in our economic welfare assumes 
unusual importance. In planning research in the field of bee culture 
it is therefore imperative that consideration be given whenever pos- 
sible to the use of bees in pollination. 
HONEYBEES IMPROVE SET OF ALFALFA SEED 
A survey of alfalfa fields in Utah in 1943 showed that honeybees 
outnumbered the wild bees in the ratio of 1,000 to 1. Pollen-gathering 
honeybees tripped practically all blossoms visited, and in some areas 
more pollen was gathered from alfalfa than from all other plants, in- 
dicating that a substantial amount of pollination is effected by honey- 
bees. Nectar-gathering bees, on the other hand, tripped only about 2 
percent of the blossoms visited, but because of their preponderant 
numbers they are unquestionably an important factor in the production 
of alfalfa seed. Methods of handling bees that stimulate them to 
gather maximum quantities of alfalfa pollen should improve seed 
production. The proximity to alfalfa fields of competing mustard, 
thistle, sweetclover, corn, and other plants has an important bearing 
on the distribution of pollinating insects in the alfalfa. 
The yields of alfalfa seed in Utah declined from 6V2 bushels per 
acre in 1925 to IV2 bushels in 1942. This decrease in productiveness 
may be attributed largely to the decimation of native pollinating in- 
sects and to an apathetic beekeeping industry caused by years of 
low honey prices. 
INSECTICIDES VS. BEE LOSSES 
Samples of bees from 115 dead colonies in Utah analyzed for 
arsenic showed that 95 contained sufficient arsenic to account for their 
death. Analyses of pollen stored in the hives in G3 dead colonies 
showed that 54 contained lethal amounts of arsenic. As little as 3 
parts per million of arsenic trioxide in pollen was found to be harm- 
ful to the bees. Dusting operations on cotton and tomnto crops in 
Arizona and California were responsible for the death of more than 
10.000 colonies last year. 
Although arsenic is the chief cause of bee poisoning, tests with DDT 
and with dinitro-o-cresol, both new spray materials the latter of 
