1912] Brijant: L'clation of Birds to a Grasshopper Outbreak 3 



4. In what measure may birds be instrumental in preventing 

 and controlling grasshopper outbreaks and what regulatory ac- 

 tion maj- they have at other times ? 



Certain sections of California are annually troubled with 

 grasshoppers, and there is seldom a year when they do not 

 cause considerable damage in some part of the State. (See 

 Woodworth, 1902, and Hunter, 1905.) Eeports of damage 

 caused by grasshoppers in 1912 first began to appear in June. 

 The western part of Merced County, and parts of Kings and 

 Kern Counties, were most affected. 



The present investigation was largely carried on in the vic- 

 inity of Los Banos, Merced County, this being one of the worst 

 centers of infestation. A comparison of the bird population in 

 the infested area was made possible by a census taken in the 

 vicinity of Merced, a city in the western part of the county. 



Alfalfa, pasture, grain, and a little fruit, form the principal 

 crops raised in and near Los Banos. Grasshoppers give some 

 trouble in this vicinity each year, but in 1912 their depredations 

 were more extensive than usual. Grasshoppers were abundant 

 enough to do serious damage in only three districts in the near 

 vicinity of Los Banos. The area most infested is known as 

 "Section Four," one of the ranches of the Miller and Lux Com- 

 pany, eight miles west of the town. The Midway Ranch, four 

 miles east, was badly infested and a slight infestation existed one 

 and a half miles south. On the two ranches mentioned the entire 

 summer crop of alfalfa was destroyed. Burning over of pa.sture 

 and of alfalfa land was the only control measure resorted to. As 

 most of the grasshoppers already had wings when the burning 

 w-as done, most of them escaped unharmed. Fields of alfalfa 

 outside of the infested districts looked well, and many of them 

 were being cut. 



Garden vegetables and small trees in the infested areas suf- 

 fered. Corn, tomatoes, and onions were stripped of every leaf. 

 Small shade trees, including eucalyptus, were also defoliated. 



A single species of grasshopper, Melanopliis differentialis, the 

 differential grasshopper, caused the damage. In pasture land a 

 few grasshoppers of the species Camnula pellucida were col- 



