BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 65 
moved into the locality from another alfalfa field. For example, a 
group of colonies moved to an alfalfa field from a mountain location 
devoid of alfalfa collected an average daily weight of alfalfa pollen 
almost twice as large as the group moved from another alfalfa field. 
These observations were made from weight data and from deter- 
minations of the floral sources of more than 1,200 samples of pollen 
pellets collected in 1951 in pollen traps placed at the entrances of hives 
located in an alfalfa field. 
Bee-Trapped Pollen Withstands Subzero Temperatures 
Bee-trapped almond pollen was found viable after being stored for 
a year in a deep-freeze at —13° F. This was disclosed during experi- 
ments at Davis, Calif., in cooperation with the Pomology Division of 
the California State College of Agriculture, to compare the value for 
artificial pollination of fruit tree blossoms of fruit pollen trapped 
from bees and hand-collected pollen, each of which had been stored 
over winter. 
Insecticides on Cotton and Alfalfa Cause Heavy Bee Mortality 
Bee mortality from insecticides applied to cotton in Arizona was 
the greatest since the years of widespread use of arsenicals. Para- 
thion and BHC were the insecticides that were particularly lethal to 
bees. The highest mortality resulted from direct applications and 
drifting of these materials to apiaries. Honey yields were low in 
many apiaries because of the repeated destruction of field bees. 
Observations were made of the behavior of a bee colony suffering 
from the effects of BHC. Within an hour after exposure to this 
chemical bees began hastily leaving the hive, tumbling, somersaulting 
in headlong flight, often tumbling along the ground 2 or 3 feet before 
taking wing, after which their further flight away from the hive 
became stable. Others unable to fly, tumbled and gyrated over the 
ground near the hive entrance and eventually died. 
When the hive cover was removed the bees were found to be much 
more agitated than usual. They reacted in a very agitated manner to 
the first puff of smoke and became mean. As more and more of the 
affected bees poured out of the hive entrance, bees remaining within 
became less organized and gathered in small clusters, each cluster 
appearing like that formed when a queen is being ''balled/' All or 
most of the bees vacated the hive to cluster near the entrance or in 
nearby treetops. The queen accompanied the bees, although this does 
not always occur. With all adult bees gone, the sealed brood died 
in the deserted combs. The larger larvae crawled from their cells 
to succumb on the bottomboard, while younger larvae died in their 
cells, probably from starvation rather than poisoning. Adult bees 
that recovered from the poisoning returned to the hive within a day 
or two. From other observations, it has been found that if the queen 
and enough of the adult bees survive, the colony begins to recuperate. 
In Utah an evening application of (> ounces" of TEPP per acre of 
alfalfa killed 4- percent of the average daily population of honey bees 
visiting the field. Early morning applications of 2 ounces of aldrin, 
6 ounces of TEPP, 10 ounces of malathion, or 4 ounces of heptachlor 
per acre resulted in respective mortalities of 7, 21, 30, and 35 percent. 
Insecticides that cause more than 10 percent mortality under the condi- 
