EJGIITEENTH ANNUAL REPORT OF STATE ENTOMOLOGIST ^ 



City in ]i»01. Both the JCxpcriment Station of Utah and the United 

 States Department of Agriculture took steps to bring- it under con- 

 trol and there has been maintained a branch ofhce of the United 

 States Bureau of Entomology at Salt Lake City ever since, tlie pur- 

 pose of which is to study this insect alone. 



Many farmers in Montana who have not had experience with 

 this weevil beliexe it to be a destroyer of the seeds of alfalfa. This 

 is not the case, as the small green-colored worms hatching from 

 eggs laid by the small beetles feed entirely upon the foliage and 

 stems of the growing plants. So serious has this insect become 

 that it has in many cases almost completely destroyed the hay crop 

 in infested lields and has Ijeen so prevalent in localities where it 

 has been established for a long time as to seriously interfere with 

 the production of alfalfa. Many growers have given up the attempt 

 •to grow this crop and the whole agricultural industry has been 

 seriously affected. 



This insect has spread from year to year, its extension having 

 gone mainly northward. It is now present in practically all portions 

 of Utah where alfalfa is grown, much of southern Idaho, a few- 

 counties in eastern Oregon, and in certain counties in Colorado and 

 Wyoming, Its northward extension has reached almost to the Alon- 

 tana boundary, as it is now present in the first county across the 

 Montana line in Idaho, namely, Fremont County. 



The alfalfa weevil spreads overland from field to field and is at 

 first generally present in such small numbers that it is not detected 

 many miles in advance of where it is doing damage. For this reason 

 it may be already in Montana. It has in a few instances been car- 

 ried, in connection with industry, into remote localities. In this way 

 it appeared in Delta County, Colorado, and in Payette County, Idaho, 

 each of which localities is l^ecoming a new center of distribution. 

 We believe that the main source of danger is the shipment of alfalfa 

 hay, and Montana's quarantine which has been in force since 1913 

 has been aimed mainly at the prevention of shipping alfalfa hay 

 into Montana from infested localities. The quarantine was raised 

 in the spring of 1920 and large amounts of alfalfa hay were shipped 

 in from southern Idaho and were distributed widely throughout the 

 state, thereby relieving a very serious shortage of hay. It is possible 

 that the weevil was introduced at the same time. Because of these 

 shipments of hay from Idaho and because of the danger v,-hich con- 



