INSECT PEST SURVEY 3 U I I J T I S 
Vol. 17 Supplement to lumber 1 March 15, 1937 
ALFALFA WEEVIL SURVEY, 1 FAIL OF 1936 
W. C. KcDuffie, Junior Entomologist 
Division of Cereal and Fora ge Insect Investigation s 
Bureau of Hint omo logy and Plant Quarantine 
U. S. Department of Agriculture 
PURPOSE OF SURVEY 
Fall survey of alfalfa weevil abundance was initiated in 1932 in order 
to indicate the outlook for damage in the following year and to build a 
reliable record of annual regional abundance which may later be used in 
studying effects of climate on the weevil. The abundance of overwintering 
cocoons of the larval parasite Bathyplectcs curculionis Thos. was obtained 
from survey samples and the percentage viability of these was determined by 
dissection. 
aXTiSTT OF SURVEY 
Districts surveyed were restricted to those regions most important 
both in regard; to alfalfa and to prevalence of weevil damage in recent 
years. Twelve districts were surveyed. These included parts of Oregon, 
Idaho, Colorado, Nevada, Utah, and Nebraska. The sampling plan was modi- 
fied from that used in previous years in that the number of samples per 
field were reduced and the number of fields in a district were increased. 
Four samples were taken in each field and 25 fields in each district. This 
gave a less accurate figure for each field but a more useful indication of 
the general level of weevil abundance in a region. 
^ Hypera postica G-vll. 
2 
The work on which this report is based was carried out under the 
direction of J. C. Hamlin. The author was assisted by F. V. Lieberman, 
R. C. Newton, R. W. B\inn, and L. J. Jones. 
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