BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 55 
in the southern end, but the bulk of the crop began about 18 miles above! 
Tucson, extending northward about 12 miles. About 2,000 acres of Pima or 
long-staple cotton and 5,000 acres of short-staple cotton were grown, and a 
gin for long-staple and a gin for short-staple cottons were operated. Prac- 
tically all trash produced was inspected with a gin-trash machine, with nega- 
tive results. Toward the close of the ginning season field inspections were 
made of the top crop of bolls, and a light infestation of Thurberia weevil was 
found about 3 miles north of Tubac, in Santa Cruz County, and another at 
Saliuarita, 18 miles south of Tucson, in Pima County. A supply of bollies 
was collected, and at the end of the year examination of this material bad not 
quite been completed. A few specimens have been found in material from 
three additional fields, all located near Tucson. None of the material from the 
Rillito-Marana district, where the bulk of the crop is grown, has been infested. 
Only 30 specimens have been found, which, together with the negative gin-trash 
inspections, indicates that there is a very light infestation in the top crop 
of bolls. 
The measures used in controlling and preventing the spread of the Thur- 
beria weevil are the same as for the pink bollworm. These consist of disposal 
of gin trash, sterilization of seed, compression, fumigation, and roller treatment 
of lint, and the clean-up of gins, oil mills, etc., at the end of the season. The 
results of each of these activities are included in the figures given for the 
pink bollworm. 
BEE CULTURE 
Pollination studies on the Pacific coast show that bees shift their activities 
to fruit varieties in accordance with the sugar concentration of the nectar. 
Fruit-tree varieties within the same species were found to show wide variation 
in nectar concentration, resulting in wide variability in the pollenizing effec- 
tiveness of bees. 
Cooperative studies with the University of California on the cost of honey 
production indicate that the average cost is 6.9 cents per pound, while the 
average price received by producers during the year was 4.5 cents per pound. 
Of 225 California apiaries studied in 1933, 8 percent made a profit, 8 percent 
broke even, and 84 percent operated at a loss. Similar conditions prevailed 
in 1934. 
Uncontaminated beeswax is known to be white, but white wax required for 
the manufacture of candles, cold creams, etc., has been difficult to prepare 
from the crude brown and yellow western beeswaxes. Studies in cooperation 
with the University of California have shown that brown stains were caused 
by iron rendering utensils. Wax rendered in glass, aluminum, and stainless 
steel was white or yellow. The source of yellow pigment was found to be 
pollen, although some pollens do not impart color to beeswax. 
Loco weed (Astragalus trichopodus) was found to cause a wide-spread death 
of adult bees in southern California. It was likewise found that Matilija 
poppy [Romneya coulterl) also affects adult bees. Four other plants, three of 
which occur in California, are now definitely known to be poisonous to bees. 
The difficulty of combating American foulbrood, a contagious disease of 
bees is further emphasized by the fact that the disease has recurred in the 
experimental apiary at Somerset, Md., in combs that had been treated with 
formaldehyde and in which healthy brood had been reared for a period of 5 
years. Studies conducted in cooperation with the University of Wyoming 
in an apiary of 1,700 colonies indicated that honey produced above queen 
excluders in diseased colonies in practically all cases contains enough spores 
of American foulbrood to constitute an infectious dose. This fact is contrary 
to the general belief. On the other hand, out of 58 samples of honey, repre- 
senting a crop of 220,000 pounds from a commercial apiary in Wyoming having 
a more or less constant infection of American foulbrood, all showed a spore 
content less than the minimum infectious dose. 
Work is under way to test the resistance of Caucasian, Carniolan, and 
common black bees to European foulbrood, another contagious disease of bees, 
and although it. is generally conceded that this disease can he readily eon- 
trolled, an unusually virulent type of this disease has been found in NVw 
England. The indications so far are that this particular strain is not amen- 
able to the usual methods of treatment. 
Surveys of pollen reserves in commercial apiaries in the Intermountain 
States bear out the result of previous experimental work that an abundance 
