48 THE ORTHOPTERA OF MINNESOTA. 



Gyps^'-moth, so destructive in Massachusetts. Hiding dur- 

 ing the day, but very active at night, are also other large 

 ground-beetles, belonging to the genera of Pasimachus and 

 Scarites ; especially the former are very fond of young lo- 

 custs and have been seen devouring them in great numbers. 

 Many other beetles, flies and wasps are known to leed 

 upon locusts, or to use them as food for their young. But 

 enough has been shown to indicate that the life of a locust 

 is not one constant round of pleasvire. This becomes ver}' 

 plain if we consider that besides the enemies already men- 

 tioned the locusts are badly invaded by internal parasites, 

 for instance by that curious being, the Hair-snake {Gordius 

 species). If we remove the head of a parasitized locust we 

 sometimes see its whole interior filled with this parasite, 

 which is many times as long as its host, and it will be seen 

 that all the important organs of the locust are compressed 

 and unable to perform their necessary functions, hence the 

 insect looks "pale and sickly." 



OTHER ENEMIES OF THE LOCUSTS. 



A large number of birds and animals eat locusts when- 

 ever they have a chance to do so. Domestic fowls eat them 

 greedily, but soon tire of this diet if the insects become very 

 numerous. Most active of all in destroyinglocusts is a small 

 tern, the Black Tern, [Hydrochelidon nigra svrinamensis), 

 which is very common in the prairies, even many miles from 

 any water. It and the Ros3'Gull {Lams Franklini), are con- 

 stantly engaged in catching the young locusts, for them- 

 selves as well as for their 3'oung. Both species of aquatic 

 birds follow the plow, very much in the same wa\' as the crow 

 is in the habit of doing elsewhere. The various species of 

 blackbirds, such as the Yellow-headed Blackbird (Xantho- 

 cephalus xanthocephalus) ; the Red-shouldered Blackbird 

 {Agelaws phoenlccus); the Rusty Blackbird {Scolecophagus 

 carolinus); the Bronzed Crackle {Quiscalus quiscula aeneus); 



