MONTANA INSECT PESTS 1945-1946 13 



conditions for the poor growth and sickly appearance of their fields, 

 because they did not realize that the weevil was causing the dam- 

 age. Although the activities of this insect are greatest during the 

 growth of the first cutting, many fields were so badly damaged 

 that second and third hay crops as well as seed production were 

 considerably reduced. 



Information concerning the alfalfa weevil and its control was 

 published in local newspapers and distributed through county 

 agents' offices in an effort to reach as many farmers as possible. The 

 majority of operators were unable to do control work, because they 

 did not have spraying or dusting machines, and dealers were not 

 able to obtain such equipment. The present indications are that 

 sprayers and dusters will be on the market next spring and will be 

 available in sufficient numbers so that farmers wishing to do con- 

 trol work can obtain equipment. 



A bulletin on the alfalfa weevil and its control has been pre- 

 pared and will be distributed through the county extension agents' 

 offices before spring. 



Unless conditions are unfavorable for the weevil, it is expected 

 that the infestations in 1947 will be as severe as last year and that 

 the area affected will be larger. 



CLOVER ROOT CURCULio (Sitona spp.) .—This small, grey 



broad-nosed weevil was found causing injury to alfalfa in the Yel- 

 lowstone Valley in 1946. Larvae and pupae were removed from 

 typically injured roots collected near Worden, Montana, by County 

 Agent W. H. Jones, on June 27. Injured fields were seen in Still- 

 water and Yellowstone counties. 



Clover root curculios attack several legumes including alfalfa, 

 the common clovers, cowpeas, soy beans, and possibly others. Plants 

 attacked by these pests wilt and may die. Injury is most obvious 

 during periods of dry weather. Roots of affected plants will be 

 found to have the surfaces scored and furrowed, almost to the 

 extent cf complete girdling. This injury is caused by the grubs 

 v/hich are pale, legless, brown-headed, and about one-sixth of an 

 inch in length. Clover root curculios usually spend the winter as 

 small grubs and feed on roots in the spring. The adult beetles feed 

 on the leaves in late spring and early summer. 



An effective control for the clover root curculio has not as yet 

 been devised. Late fall or early spring plowing has been found to 

 assist, and rotation with grasses or cultivated crops will drive the 

 pests from the fields. Treatment, during the period of adult feed- 

 mg, with some of the newer insecticides may be of value, but ex- 

 perimental data are lacking. 



