54 AL iM:r(»i:rs ui- i >i:r.\Ki-.Mi:N'r of .\< ;ki( i i/rrii]:. i'.imt 
Tlie majority of tin* coKoii acrcM^rf is in the Maraiia section, about is niik'S 
iiortliwcst of 'J'ticsoii. Most of til" siM'ciiiKMis caiiic from the small acreage 
south of 'J'mcschi, 
The native host of the Tlnirhcria weevil is Thurb< rin theain nioid( H Gray, a 
nialvaceoiis i)laiit closely related to (-(jttoii. This plant occurs in a number 
of mountain ranges in southern Arizona, particularly the Tortollita and Santa 
Catalina Kanges, which are nearest to the cultivated cotton, and the infested 
plants furnish a continuous source of reinfesialion to the eultivated cotton. 
In V.'.'^Tt emergency relief fluids were provided hy the \V. V. A. U) attempt 
eradicati(»n of the plants and thus remove the menace from cultivated cotton. 
Active work was begun in August VX\Tt and has been continued throuirhout the 
I)resent fiscal year. Work in the Tortollita Uange was completed early in 
ID.'iO. and since that time work has been carried on in tin* Santa ('atalina 
Kange. In the beginning the laborers were transported in trucks to and 
from Tucson each day. As soon as all of the area readily accessible from 
Tucson had been worked it was necessary to establish a camp in the moun- 
tiiins. The camp had to be moved several times as various sections were 
completed. During the fiscal year 6.">.24.~) acres were worked in the Santa 
Catalina Range and r»()L:.4SS TJnirhrrin plants destroyed. Many (»f the.'ie plants 
were heavily infested with the Thurlteria weevil. Since the w<»rk ha.s been 
under way over l.UUU.UX) Thurlxrin plants liave been (lestroye<l. 
BEE CULTURE 
This season 400 packages of bees have been under observation in tiie apiaries 
of cooperators in a continuation of the supersedure study. In last season's 
work, of 606 queens for which complete records have been compiled. 8.ii6 per- 
cent wore lost in shipment or by other manipulations, 8.1M> by super.sedure, and 
8.3 percent were replaced by the beekeeper within 2 months after receipt. This 
indicates that the country's annual loss of (pieens may be as high as 20 percent 
from the forc^going causes alone. During the preceding season it was found that 
supersedure is little intluenced by a variation in populati(»n of a colony such as 
that occasioned l)y adding brood or bee.s. During the current .<ea.son the effect 
of the availability of pollen is being observi'd. So far the shipping of queens, 
either in mailing cages or in packages of bees, appears to have no etTtn-t on the 
amount of supersedure. 
rreliminary work indicates that with proper equipment, good management, 
stimulative feeding, and an early pollen supply, good colonies in the South can 
produce at least 20 poiuids of package bees in one .«eason. 
With the cooperation of the Vanderbilt Medical School it was fouml that 
vitamiti E is not present in royal .ielly. The vitamin A and W content is now 
being studied in a continuation of the endeavor to find why queen and worker 
become dilTerentiated from (>ach other. 
P>eekeeping in the Sierra Nevada and Ca.scade Mountains has been subjected 
to serious losses by bears. With the cooperation of the Zoology and Agricul- 
tural Engineering Departments of the University of California, an electric fence 
charged from a battery has been devised that has worked succi^ssfully in keei>- 
ing bears out of apiari(vs when a good ground was provided for the electric 
current. 
Cooperative work with the Oregon Agricultural Exju'riment Station showed 
that nectar from floral nectaries of various vetches under observation con- 
tained a lower sugar concentration than did nectar from the extratloral n»H*- 
taries of the same plants. For this reason bees ignored the blossoms in favor 
of the extratloral nectaries. Hairy vetch proved an exception, since the sugar 
concentration of nectar from the blossimis was higher tlian that frt»m the extra- 
floral nectaries. Conse(|ueiUly b(>es workt^l the Ilowers of this i)l.Mnt. The 
stigar content of lu'ctar from alsike and crimson clovers compared favorably 
with that of vetches in blossom at the same time. Ne<tar from re«l clover was 
scarce and of a low sugar concentration not attractive to bees. 
Work was begun on testing vari(»us races and strains of bees for resistance 
1o Ameri<-an fonn)rood by th(> inoculation of colonies with detinite dosagi's of 
the causative organism. Thirty-nine (pieen l>ees from stock hehl to have shown 
some degree of resist an< e were accunndated in ll>.'i«'» and 12 of tlnMU w«»re tested 
'u\ colonics. Four showed more or less indlcati«»n of resistau<e since they 
<-leaned up the slight amount of disease developing as a result of iiKH-ulations. 
The standard dose being used for the inoculation tests <'onsists of 10 times 
the miniiiinni infectious dose or .">(>0.tKH» spores jum" cubic centimeter in 1 liter 
