SUMMARY OF INSECT CONDITIONS DURING 1921. 



23 



while the remainder of the season was comparatively warmer. (See 

 Table 5 and Fig. 10.) 



The rainfall over this region was above normal during the fall and 

 early winter. During the early spring slight droughts occurred 

 during March. The remainder of the spring and summer were 

 slightly above normal. September of 1921 showed a deficiency of 

 about | inch. (See Table 5 and Fig. 10.) 



Figure 9 illustrates the area known to be infested in 1921. The 

 shaded area is generally infested and the black dots are definite 

 localities where the pest has been collected. 



+ 5 



+ <? 

 +3 

 + 2 



+ / 



\ 



- / 



-3 



-4- 



^\ 



pjfefe 



- -0.+ 



- -0.2 



-I.O ^ 



-0.8 & 

 | 





k r, P 



^ $ s 



^ t ^ 



/320 



/92/ 



+/.0 x 



Fig. 10. — Monthly departures from normal temperature (solid black) and rainfall (white) 

 from September, 1920, to September, 1921, inclusive, in the region infested by the 

 alfalfa weevil. (See also Table 5.) 



Table 5. — Montldy departures from normal temperature and rainfall from 

 September. 1920, to September, 1U21, inclusive, in the region infested by the 

 alfalfa weevil. 



DEPARTURES (IX DEGREES FAHRENHEIT) FROM NORMAL TEMPERATURE. 





1920 













1921 













Sept. Oct. Nov. 



Dec. 



Jan. 



Feb. 



Mar. 



Apr. May. 



June. 



July. Aug. 



Sept. 



Wyoming 



Idaho 



-0.1 -0.5 -3.7 

 -.0 -2.1 -.7 

 -.3 -2.1 -1.2 

 -.4 -2.2 | -.7 

 -.9 -.7 -2.4 

 -.1 -2.7 -1.1 



-1.4 

 -2.3 

 +2.0 



-.2 

 -2.8 



-.4 



+3.8 

 -3.4 

 -1.5 

 -3.7 

 -3. 7 

 -2.6 



+5.1 



+.9 

 +1.9 

 +2.9 

 +3.6 



+2.8 



-4.3 

 +2.8 

 +1. S 



-2.6 



-2.9 



14 



+ 1.2 



4-3 



-3.3 

 +2.8 

 -2.2 

 -2.1 

 -.5 

 4-2 2 



+1.3 



+.6 

 -1.0 

 +1.2 



+.5 

 +1.6 



+0.8 

 +1.0 



-.1 

 -.3 

 -.1 

 -.1 



-0.7 



-3.9 



2.3 



Utah 



Colorado 



Nevada 



-4.il -3.1 +.8 

 +4.9 -2.3 +1.5 

 +4. 1. 8 +. 



-.8 

 + 1.1 



4 





' 





Regional mean. . .. 



-.3 -1.7 -1.6 



+.5 



+3.1 



+ 2.9 



+3.6 -2.3 +.S -2.2 -.7 -.3 



-" 



DEPARTURES (IN INCHES, FROM NORMAL RAINFALL. 



Wyoming. 



Idaho 



Oregon 



Utah 



Colorado... 

 Nevada... 



Regional mean. 



-0. 33 -0. 2S -0. 10 -0. 08 -0. 04-0. 48 -0. 34 

 -.29-1.02 -.19 +.83 +.18 +.00 -.15 



1.35 -.19+1.90 +.74+1.31 

 -.26+1.77 -.12 +.23 +.05 -.39 

 -.27 -.32 -.09 -.24 -.05 -.47 

 -.18 -.24 -.04 -.08 -.22 -.39 



-0. 19 -0. 06 +0.36 -0. IS -0. 27 -0. 77 



.40 -.43 +.05 

 -.21 +.19 -.02 -.OS -.50 -.23 

 -.33 +.71 +.40 -.22 +.01 +.95 

 -.10 +.72 -.39+1.52 +.36-1.17 

 -.56 -.09-1.12 -.05 -.16 +.09 



+.18 



83 



05 



07 



2v -.2- +.32 +.18 



-.15 +.29 



-.30 

 -.01 



-.97 

 -.22 



