Insects 151 



varying from 43 to 61 mm. in length. The wings are vestigial, 

 represented by rounded, speckled pads. It would seem as if 

 Nature had abandoned the attempt to support such a heavy 

 insect in the air. The curious thing is, that this type of evolution 

 has occurred more than once, for the equally large lubber grass- 

 hopper of the southern states, Rhomaka, has a spine between the 

 front legs, and belongs to the next subfamily. 



The subfamily Acridiinae or Cyrtacanthacrinae* (Locustinae 

 of Comstock's Introduction) is easily recognized by the possession 

 of a conspicuous obtuse spine on the prosternum, between the 

 bases of the front legs. It is to this group that some of the 

 large migratory locusts belong. Discussions arise as to the 

 precise meanings of the words locust and grasshopper. Actually 

 there is no difference, except that it is common to call species 

 which are either large or destructive locusts. The migratory 

 locust of historical fame is quite large, but the Rocky Mountain 

 locust is really an ordinary-looking grasshopper, which became 

 a locust in popular estimation because of its ravages. This 

 migratory insect, called Melanoplus spretus, was first described 

 in 1865, and its migratory hordes did so much damage in the 

 Western States that a special Government Commission was 

 appointed to study it and devise remedies. The swarms, ap- 

 pearing like dark clouds, were capable of travelling as much as 

 500 miles from the point of origin, and when they descended, 

 they made short work of the crops. In spite of these invasions, 

 the locusts did not permanently establish themselves in the 

 localities they reached, and when the breeding grounds in the 

 Dakotas, etc., were for the most part plowed up and put into 

 cultivation, the swarms became a matter of history. It is safe 

 to say that no invasion of the Rocky Mountain locust will ever 

 occur again, and indeed Professor Gillette of the Colorado 

 Agricultural College said in 1904 that during 13 years of col- 

 lecting, during which he had obtained enormous numbers of 

 grasshoppers, he had failed to find a single specimen. In fact, 

 no resident of Colorado has taken a Melanoplus spretus in recent 

 years, so far as I can learn; supposed specimens always seem to 



*Rehn and Hebard use Cyrtacanthacrinae for Acridiinae of authors, AcridinaeforTruxali- 

 nae of authors, and Acrydiinae f or Tettiginae of authors. All these they place withOedipodi- 

 nae in a family Acrididae. 



