﻿OF THE STATE ENTOMOLOGIST. 171 



rated by the Mississippi Valley — a fact proved alike by spretus'' dying 

 out on the limit line I have mapped, and by its perishing when arti- 

 ficially transported in the egg and hatched in the Atlantic States.* 



It is in this, as it is in almost every other instance where large ma- 

 terial from widely different parts of the country is examined ; the 

 lines which are easily drawn between species characterized from single 

 individuals, break down, and continually remind us of the arbitrary 

 nature of specific definitions, and of the fact that most of the species,^ 

 as defined among lower animals and plants, have no real exis- 

 tence in nature. There are races of femur-ruhrum which approach 

 even the larger differ entialis as much as they approach sjpretus. In 

 short, without speculating on the common origin, in the past, of all 

 these species — and, indeed, of all species composing present genera — 

 we behold, in a broad sense, a short- winged species {femur-ruhrum} 

 common to the whole country between the Rocky Mountains and the 

 Atlantic, giving way, in the higher altitudes alike of the Rocky 

 Mountain and the White Mountain, and probably of the Alleghany 

 regions, to a longer- winged one; and the reason why the western 

 long-winged species is more disastrous than that of the East, is doubt- 

 less due to its larger size and to the larger extent of table land in 

 which it breeds, as well as to the fact that the western climate is more 

 subject to excessive drouths, which cut off the supply of nourish- 

 ment at a time when the insects are acquiring wings, and thus 

 oblige them to migrate — such conditions occurring much more rarely 

 in the home of the eastern species. The future orthopterist, as he 

 studies material from all parts of the country, will very likely write :: 

 Caloptenus femur-ruhrum,, DeGeer., var. 5/>/'6^ws Thomas, var. Atlanis 

 Riley; but the broad fact will remain that these three forms — call 

 them races, varieties, species, or what we will — are separable, and 

 that they each have their own peculiar habits and destiny. 



INJUKY FROM OTHER NON- MIGRATORY LOCUSTS. 



Almost every year, in some part or other of the country, we hear 

 reports of injury by locusts. In 1868, for instance, while the Rocky 

 Mountain species was attracting attention, as I have already stated, 

 (p. 137), in many parts of the West, other non-migratory species were 

 extremely injurious in the Mississippi Valley, and in the Eastern 

 States. In Ohio they appeared in countless myriads during that year, 

 and at the meeting of the Cincinnati Wine Growers' Society it was 

 stated that they invaded the vineyards, destroying entire rows, defoli- 



*See an observation by Mr. S. S. Rathvon, of Lancaster, Pa., who concludes, from experiment, 

 that the climate there is ' ' unwholesome' ' to the species. [Am. Entomologist, II., p. 88. ) 



