50 ANNUAL REPORTS 01 DEPARTMENT OF AGRICULTURE, 1952 
In Washington County (southwestern Utah) a complex of 
wild bees and pollen-collecting honey bees were all important and 
doing a L r <><<'d job. In south-centra] Utah and an adjacent area of 
Arizona, noney bees | from 1 to 5 percent pollen collectors) and bum- 
ble bees (B. morrixoni) were responsible for a moderately good 
pollinal ion job. 
Alfalfa Pollen Varies in Attractiveness to Her- 
Ii is increasingly evident thai differences exist between varieties 
in fields of alfalfa which affect bee collections of both nectar and 
pollen. Anions several variet it'- of alfalfa observed in Kern Count v. 
( 'ali f.. one was pracl ically devoid of pollen-collect ing honey bees early 
in July, although such bee- were numerous on the other varieties. 
Sinee pollen collectors are highly efficient trippers of the blossoms, a 
pooi- set was being obtained on this one variety. Later in the season, 
however, a- the other varieties became bent down with seed and de- 
creased in attractiveness, the bees collected pollen from the previously 
neglected variety, which was -till in good blossom. All these fields 
were supplied with about 3 to 4 colonies of bees per acre for the purpose 
of increasing seed set. 
Fewer Bees Needed for Alfalfa Pollination in Absenee of 
Competitor Plants 
Plants that compete with alfalfa a- a source of pollen are scarce 
in the San Joaquin Valley a- compared with the Sa< ramento Valley 
of California, a situation which would indicate a more rapid seed set 
ami the need tor fewer bee colonies to accomplish pollination of an 
acre of al falfa in t he former than in the latter valley. ( )bs&T\ ations 
this past summer bore out this assumption. It was found that at 
Bakersfield as few a- 3 colonic- per acre set heavy yields of seed in 30 
day-, whereas at Woodland even 6 colonies i er acre required 60 days 
or more to set a heavy crop. The \n-t^ collected only nectar at Wood- 
land. When bees visit alfalfa -imply for nectar, their efficiency in 
effecting pollination of this plant is low. Yields of 500 to 1,000 pounds 
of alfalfa seed per acre were nevertheless obtained from many fields 
in hot h localit ies. 
COTTON INSECTS 
Pink Bollworm Control and Research Activities 
H idespread dispersion of pink bollworm poses serious threat 
Never before in the 35 years since the pink bollworm first entered 
the cotton fields of T< icas has the situation been so serious as it is 
There has been an alarming spread in recent years of this most 
destructive cotton pest. Farmers, educators, extension and research 
cies, and the entire cotton industry are being urged to form a 
unified team to carry out the recommended cont rol program in a man- 
ner to again suppress it and to keep it below a level where commercial 
damage results. The life history of the pink bollworm is such that it 
is much more susceptible to cultural control measures and cottoi I 
heat treatment than many other cotton pests. 
