TWEXTV FlI'TII U'EPORT OF 8TATE ENTOMOLOGIST 9 



GRASSHOPPERS IN 193i 



By Noveiiiher 1, 19.33, it was establislied beyond any doubt that 

 ^Montana would experience in 11)34 the worst grasshopper outbreak 

 in its agricultural history. Eiji:liteen counties were so infested with 

 eggs (see figure 1) that from 50 to 90 per cent of the total acreage 

 in grain and hay crops would have to be treated with poisoned bran 

 mash. Eleven other counties showed infestations ranging from 25 

 to 50 per cent. Furthermore, these twentj'-nine counties were the 

 ones which produce in most years 90 per cent of our spring wheat 

 and nearly 50 per cent of our tame hay. In manj' of these counties 

 the eggs of the lesser migratory grasshopper (Melanoplus mexicanus) 

 were so abundant that as high as 30 egg pods, each containing about 

 20 eggs, could l)e found per square foot of stubble. The estimated 

 cost of combating such an extensive outbreak was beyond the finan- 

 cial resources of the state. 



Figure 2. — Tlie intensity of the 1934 grasshopper outbreak. This indicates 

 where the grasshoppers actually were. 



