284 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. xx. 



"]/. devorator was founded upon specimens of strikingly contrasted 

 coloration found in Texas, which I have since seen from many other 

 places; but as they are united with the type by complete series of 

 intergrades, I am forced to conclude them to be only extreme color- 

 ational variations, which can not be dignified even as races. 



Specimens with green or greenish hind tibiae have been seen by me 

 from the alpine region of the White Mountains, New Hampshire, Cape 

 Cod, Nantucket, Great Island, and Cambridge, Massachusetts, Utah, 

 Carrizo Springs, Texas, and Querataro, Mexico. 



There can be no doubt that this is the true femur-riibrum of De Geer, 

 since Stal has described the anal cerci of the male from the type of 

 De Geer's description, and I myself made direct comparisons with 

 varied material when in Sweden, nearly thirty years ago. 



In Hayden's report on the survey of Nebraska (1872), I collected 

 several accounts, printed and unpublished, of the injury to crops attrib- 

 uted to this species in the eastern United States. As up to that time 

 M. atlanis had not been distinguished from M. femur rubrum, it is pos- 

 sible, and I am now inclined to think it probable, that all the serious 

 injury done to crops in the East is done by M. atlanis; for although 

 almost everywhere less common than M. femur -rubrum, M. atlanis has 

 been shown to have the capacity for immense multiplication, and has 

 been directly proved to be the culprit in some instances; as it is also 

 much more closely and indeed very closely related to the destructive 

 locust of the West, M. spretus, it is far more likely to have been the 

 actual pest in all the records of the past. At least until direct provable 

 charges are made against it, M. femur-rubrum should be looked upon 

 as less injurious than M. atlanis ; it is especially doubtful whether it 

 ever migrates in aerial swarms; as a general rule the tegmina and 

 wings are longer in M. atlanis than in M. femur-rubrum, though both 

 species vary considerably and intergrade in that particular. From 

 measurements made on Missouri specimens, Eiley found that the teg- 

 mina in the present species extended beyond the abdomen as follows: 

 In 28 males, 0-2 mm., average, 0.8 mm.; in 54 females, 0-3 mm., aver- 

 age, 1.1 mm. 



Bruner excellently expresses the fact when he says that the imme- 

 diate distribution of this insect " appears to be controlled altogether by 

 climatic conditions, the chief of which is the presence of a certain 

 amount of humidity. . . . It is a frequenter of low grounds, culti- 

 vated fields, shady margins of woods, etc., where vegetation is rank 

 and tender." It is rarely found upon dry hillsides when meadows close 

 at hand may swarm with them, while the opposite is true of other 

 species, M. collinus for instance; yet such specimens as do so occur will 

 be found to differ from those inhabiting more favored localities, in being 

 lighter colored and more uniformly grayish in tone, with slighter con- 

 trasts; those from drier stations appear also to have on the average 

 rather shorter wings. 



