168 Bryant, Birds as Grasshopper Destroyers. [April 



BIRDS AS DESTROYERS OF GRASSHOPPERS IN CALI- 

 FORNIA. 



BY HAROLD C. BRYANT. 



Considerable evidence of the interrelations existing between 

 bird and insect life has come to light in connection with investiga- 

 tions into the economic status of certain birds carried on under the 

 auspices of the California State Fish and Game Commission and 

 the University of California. Some of the best evidence came 

 from an investigation of a grasshopper outbreak in the vicinity of 

 Los Banos, Merced County, California. A part of the results of 

 this investigation was published in the University of California 

 ' Publications in Zoology,' volume 11, pages 1-20. In the present 

 paper additional matter is combined with a part of that previously 

 presented, the whole being now offered with a special view to the 

 problem of insect destruction by birds in California. 



Certain sections of California are annually troubled with grass- 

 hoppers, and there is seldom a year when they do not cause con- 

 siderable damage to crops in some part of the state. Reports of 

 damage caused by grasshoppers in 1912 first began to be received 

 in June. The western part of Merced County, and parts of Kings 

 and Kern Counties were most affected. In the vicinity of Los 

 Banos, Merced County, where the investigation was carried on, 

 grasshoppers give some trouble each year but their depredations 

 in 1912 were more extensive than usual. On many of the ranches 

 the entire summer crop of alfalfa was destroyed. The only control 

 measure resorted to was burning over of pasture and alfalfa land. 

 As most of the grasshoppers already had wings when the burning 

 was done, the majority escaped unharmed. Garden truck and 

 small trees in the infested areas were attacked by the pests. Corn, 

 tomatoes, and even onions were stripped of every leaf. In many 

 instances small shade trees, even including eucalyptus, were com- 

 pletely defoliated. 



The species of grasshopper causing the damage was the diifer- 

 ential grasshopper, Melanoplus differentialis. The only other 

 species noted at the time were Camnula pellucida, Conozoa behrensi, 

 and Parapomala calamus. 



