GRASSHOPPER CONTROL IN THE PACIFIC STATES + 
CONTENTS. 
Page. Page 
Grasshopper outbreaks___---___-__ 3 | Control methods—Continued. 
Favorable and unfavorable condi- Burning over dry areas____-_- 12 
TRESS EL eae bh ree Sed ae eet hs 4 , WSemOmaturKey Sea 2a es SS 5 
Some of the common destructive Control on the ranges—-_—___-— 13 
ATS S{SAYS) of € (2) eS eS ae ae |S) 4 Control in alfalfa fields_______ 13 
OmMMINITY ACHOn= = 2-2-2 oe ee 6 Control in orchards and vinc- 
eouErol methods = setae ees {6 VAMOS See ea = ee te 14 
The poisoned-bran mixture ____ 8 Control in mountain meadows__ 15 
Destroying eggs by cultivation— 11 Control in cultivated fields_____ 16 
GRASSHOPPER OUTBREAKS. 
The natural conditions over the Western States are such that 
grasshopper outbreaks may be expected for many years to come, 
as the immense uncultivated areas of mountains, foothills, grass 
lands, and alfalfa fields offer many varying conditions favorable 
to the abundant development of one or more of the destructive 
species involved. The earliest outbreaks occur on the warm, sunny, 
dry lands and foothills. These are followed by later outbreaks 
appearing on the cool, damp valley soils) The nymphs appear in 
greatest abundance wherever the adults have massed and deposited 
eggs in large numbers the preceding year. This massing of grass- 
hoppers is normal for some species, but may be influenced by the 
abundance of food plants or by the presence of conditions favorable 
to egg laying, such as dense crowns of bunch grasses, large alfalfa 
crowns, uncultivated gravel soils, and dry sunny hillsides. 
The destructiveness of these outbreaks depends upon many factors. 
The early drying of range grasses in June of 1919 was in part re- 
sponsible for the abundant migration in that year of destructive 
species to cultivated crops. Grasshopper migration from the foot- 
hills and range lands is not so marked when there is an abundance 
of spring rain and grasses continue green until weeds begin to grow. 
1The studies in regard to poisoning grasshoppers were extended to deciduous fruit 
orchards at the request of Dr. A. L. Quaintance, in charge of Deciduous Fryit Insect 
Investigations, Bureau of Entomology. 
178924°—20 3 
