April, ’24] 
wakeland: alfalfa weevil control 
331 
/op o p 
moA 
4QOO. 
<5 OOC' 
2£>m 
/OOP 
Extension work conducted by the University of Idaho was for three 
years based on experimental results cited above. The spray was 
applied at the time of the turning point of injury which, roughly defined, 
was when larvae became so numerous in the alfalfa tips as to cheek 
the growth of the plants. The general plan of work was to conduct 
spray demonstrations starting in communities of earliest growth and 
proceeding, as the season advanced, to those of later development and 
higher elevations. A demonstration machine equipped for alfalfa 
25 
MAY 
3 / ^ 
JUNE 
20 
Fig. 8.—One-spray application, western Colorado. Horizontal lines represent 
number of larvae collected in 100 sweeps of the net. Black area represents sprayed 
portion of field and cross-hatched area unsprayed portion. Sprayed May 27. 
Plots cut June 20. (Adapted from Eleventh Annual Report, Colo. State 
Entomologist). 
