EIGHTEENTH ANNUAL REPORT OF STATE ENTOMOLOGIST 5 



those which we always have, those present in one season may dis- 

 appear and otliers come in from other places, so that the county 

 agent is continually confronted with new^ problems with which he 

 is not familiar. It is very desirable that the legislature provide for 

 the employment of another deputy for this office, as thereby we will 

 be able to serve the farmers of the state in a much larger way. 



The species concerned in the grasshopper experiences of 1920 

 were mainly the warrior grasshopper {Camnula peUucida) and the 

 lesser migratory locust {Melanoplus atlanis), together with the two- 

 striped locust {,MeJaihO])lus hivittatus) . These were the species 

 which during the summer months appeared in enormous numbers in 

 various parts of the state. 



It is of interest to note that early in the season, beginning in 

 the latter part of February, we received reports, particularly from 

 northeastern ^Montana, that young grasshoppers were already hatch- 

 ing in large numbers. Knowing that the usually destructive species 

 did not appear as early in the season as this, steps were taken to 

 inquire into the situation and it was found that certain species whicli 

 are not ordinarily looked upon as pests had appeared in very unusual 

 numbers. The two species referred to are Stiraplenra decusmta 

 and Tlippiseiis pardalijuis. After looking into the situation we 

 reported to the farmers that we believed these insects would not 

 develop in seriously injurious numbers and the experience of the 

 season later bore out our prediction. 



Attention is being given to improving the arsenic bran mash 

 formula which is used in the control of these insects and at the same 

 time reducing the cost of the materials in the formula as much as 

 possible. This Experiment Station has found that aniyl acetate, or 

 the so-called "banana oil," may be used in place of ground lemons 

 or oranges and that the use of this chemical not only reduces the 

 cost materially and increases the effectiveness of the formula but 

 also cuts down the labor fully one-sixth. We do not possess com- 

 plete figures regarding the amount of amyl acetate used last year 

 l)ut the incomplete figures which we have clearly show a definite 

 saving in materials alone of over $2,000. 



PALE WESTERN CUTWORM 

 Within a short period of years the pale western cutworm, previ- 

 ously almost a rare insect, has become well known throughout the 



