8 MONTANA EXrERIMEXT STATION BELLETIN 238 



and Valier, the Red-legged grasshopper and the Two-striped grass- 

 hopper were very numerous in alfalfa fields while the Migratory 

 grasshopper {Melanoplus mexicanus niexicanus Saussure), which did 

 great damage in the same locality from 1928 to 1925, was conspicuous 

 by its absence. The first two mentioned species seldom cause wide- 

 spread damage over large areas, hut if their increase in 1931 is ju-o- 

 portional to tlie numbers present in the fall of 1930, considerable 

 local damage to irrigated crops may Ix' ex[)ected. 



In the dry-land section in the soutliern parts of Liberty and 

 Hill counties and in the northern part of Chouteau county, the 

 ]\Iigratory grasshopper is decidedly on the increase and is approach- 

 ing the numbers present just pre\ious to the severe outbreak of 

 1922-1924. when this species devastated nearly the whole Triangle 

 area. At least a dozen species of grasshoppers ordinarily found in 

 small numbers were unusually a])undant in sod land throughout tlie 

 Triangle area, and if they increase next year some damage to native 

 grasses is expected. 



From Havre east to the North Dakota line, along the Great North- 

 ern railroad, grasshoppers were more numerous than for several years. 

 In the irrigated sections, the T^vo-striped and Red-legged grasshoppers 

 predominated, while in the dry-land gi-ain sections the Migratory 

 grasshopper was generally the most abundant. Local damage by all 

 three species is to be expected in this territory next year, but no wide- 

 spread outbreak is anticipated. 



In the eastern end of the State, g'rasshoppers Avere on the increase 

 during 1930 in Richland. Dawson. AYiliaux, Fallon, Custer, Carter, 

 and Powder River counties, but from th(>ir present nnmbors extensive 

 outbreaks are not expected. 



Along the Northern Pacific railroad in southern Montana, from 

 Miles City to Bozeman, tlie number of grasshoppers has been below 

 normal for several years, but during tlie past season lias increased to 

 approximately the normal level. 



It is felt that 1931 will be a critical year from the standpoint of 

 gras.shopper abundance. In many localities enough eggs have been 

 laid to provide for an enormous possible increase if weather conditions 

 should prove favorable. On the other hand, it is entirely possible 

 that unusually warm weather in April may cause premature hatching 

 of the eggs, or that a prolonged period of wet weather may so reduce 

 their numV)ers as to wipe out the gains in population made during 



