MONTANA INSECT PESTS, 1953-1954 19 



POWDER POST BEETLES (Order: Colcoptcra) 



One infestation by powder post beetles was reported in Lake County 

 in 1954. This particular infestation had apparently been active for a 

 nvunber of years, and extensive repairs to the infested store were necessary. 



LONG HORNED BEETLES (Family: Ccrambicidac) 



One infestation in a log house in Cascade County was reported. Surface 

 treatment of logs with oil solutions of DDT prevent further infestation, and 

 the deep-boring lai-vae are killed by injecting insecticide into the logs. 



STRAWBERRY ROOT WEEVIL (Brachyrhinu^ ovatus) 



These insects migrate into houses in the fall in search of protected 

 quarters to spend the winter. Although they are harmless, their presence 

 elicits many requests for information about them from home owners. 



INSECTS DESTRUCTIVE TO MAN AND ANIMALS 



MOSQUITOES (Eamily: Culicidac) 



The results of the mosquito investigations in northern Montana indicate 

 that the mosquito problem in this area and similar areas is a direct result 

 of irrigation. Over 90 percent of all mosquito production in the study 

 area resulted from the farmers' use of irrigation water. Most of the condi- 

 tions that resulted in mosquito breeding were directh' related to heavy soils, 

 insufficient land preparation, improper irrigation practices, and inadequate 

 maintenance of irrigation and drainage facilities. It is also noteworthy 

 that over 70 percent of the mosquito production came from fields which 

 were being used for crops. Some of the more water-tolerant crops, such 

 as bl'ie joint, were the worst offenders. Since the mosquito problem is pri- 

 marilv related to irrigation, the need for research to determine better and 

 more efficient methods of applying and removing water is obvious. In addi- 

 tion, this research would furnish valuable information regarding the rate 

 at which water penetrates the soil, the movement of underground water, 

 and other crops and farming techniques suitable for use wherever this prob- 

 lem is present. Without a doubt, the mosquito problem in the Milk River 

 Valley has affected the entire economy of the area, for workers are reluctant 

 to enter mosquito-infested areas if work is available elsewhere. With proper 

 application of water, new crops and diversification in farming may be 

 possible. 



With improved irrigation practices, Culex tarsalis, the mosquito vector 

 of western equine encephalitis and St. Louis virus, would be decreased in 

 numbers to the point where the threat of these diseases would disappear. 

 The co-operating agencies, which include the United States Public Health 

 Service, the Montana State Board of Health, the Montana Agricultural Ex- 

 periment Station, the Blaine County Mosquito Committee, and the State 



