202 MONTANA EXPERIMENT STATION Biil. 12i 



Leaf Cutter Bees (JTegachile sp.). Certain species of trees and 

 shrubs, especially ash trees and rose bushes, suffered considerably 

 from the depredations of these insects. In one instance a few rose 

 bushes were almost entirely defoliated, only the midrib of the leaves 

 being left. 



Willow Saw-Fly {Pteronidia venin^alis) . Willows used as shade 

 trees were reported as being seriously injured by the larvae of the 

 willow saw-fly. 



Pear or Cherry Slug (EriocaTiipoides cei-asi Linn.). Cherry 

 trees in the western part of the State suffered from the attacks of 

 this pest. The somewhat flattened green slugs feed on the leaves 

 and completely skeletonize them, giving the trees a brownish appear- 

 ance. 



Ants (Fonni cilia). Ants continue to be reported as one great 

 source of trouble to the housekeeper. Usually a little concerted 

 action and careful use of carbon bisulphide will control them. 



ECONOMIC ENTOMOLOGY AND THE WAR 



The fact of the world's shortage of food supplies is now well 

 known by the American people. It is not as well known that insects 

 annually destroy about ten per cent of the agricultural output of 

 the nation — an amount sufficient to relieve to a considerable extent 

 the pressure at this critical time. The first year of the war brought 

 us in Montana face to face with several rather serious insect prob- 

 lems. Grasshoppers, mentioned in another part of this report, and 

 numerous other insects became prominent during the year and it 

 was apparent early in the season that this office could do a real 

 service by aiding the farmers to prevent losses. 



There has also grown up in recent years a very lively interest in 

 the control of ground squirrels and naturally this office had much 

 to do in directing the campaign against them. In many counties 

 the county agricultural agents cooperated with the faruicrs in the 

 preparation and distribution of poisoned grain, resulting in the 

 destruction of hundreds of thousands and perhaps millions of squir- 

 rels. There can be no doubt that this one piece of work alone saved 

 a great deal of agricultural produce during the year. 



In view of the importance of pest control work during the period 

 of the war, the department took steps to organize to meet the 

 demands for assistants. The r.^sistant entomologist, Mr. H. L. Sea- 



