4 MONTANA EXPERIMENT STATION BULLETIN 457 



stem sawfly and increased losses caused by this insect paralleled 

 the development of the practice of strip farming. It is now known 

 that this practice produces the optimum conditions for sawfly 

 activities. In the case of other pests, the reasons for their increased 

 activities are not so apparent but are in all probability related to 

 the increase in production of certain favorable host plants or the 

 adoption of certain cultural practices which may favor their 

 development. 



The complications which may arise from the indiscriminate 

 use of new organic insecticides should not be overlooked. In many 

 cases these new materials are extremely toxic to all animal life and 

 are being used so that beneficial insects such as parasites, predators, 

 and pollinators are being almost completely eliminated from 

 treated areas. The results of this usage may complicate our problems 

 greatly; however, it is too early to tell how this may effect our 

 whole insect complex. Already there are indications that serious 

 situations may arise from the promiscuous use of these materials. 

 A great deal of research and study will be necessary to properly 

 evaluate the above situation. 



It is difficult to tell whether or not livestock pests are becoming 

 more serious or whether the increased interest is because farmers 

 and ranchers are becoming insect-conscious. It is obvious that 

 stock-growers are becoming increasingly aware of the losses caused 

 by insect parasites, and are requesting information and demon- 

 strational programs to acquaint them with the insects involved and 

 the methods for controlling them. 



With the development of new insecticides that are effective 

 in controlling mosquitoes, there has been a marked increase in 

 attempts to eliminate these pests in and around urban areas. Many 

 towns throughout the state have organized control programs, some 

 of which have been very successful in eliminating mosquitoes as 

 well as flies. Other programs have not been so successful because 

 they were not correctly planned or correctly executed. Increased 

 emphasis on educational programs, demonstrations, etc., will go 

 a long way in remedying the above situations. 



HARMFUL AND DESTRUCTIVE INSECTS 



INSECTS INJURIOUS TO CROPS IN GENERAL 



GRASSHOPPER CONTROL 



1947 SEASON 



Since 1942, when grasshopper populations were the lowest 

 they had been in several years, there has been a gradual and 

 general increase in grasshopper numbers. The infestation in 1947 



