136 PHYSICAL GEOGRAPHY. 



A Manual of Economic Entomology, 

 — such a one as Harris prepared for Massachusetts — that is, one 

 similar in plan, but very different in specific detail. For one-half of 

 the insects that are troublesome in Massachusetts do not give us 

 any concern here, while the great body of our injurious species 

 were unknown in Harris' day. But while there is a great need for 

 such a work, it cannot yet be prepared, because many of our in- 

 jurious species are as yet neither known nor studied. But every 

 friend of horticulture can aid in the preparation of such a work, by 

 keeping a careful record and close notes of the habits and life-history 

 of such species as come within his observations. 



CHAPTER XIII. 



THE LOCUSTS*— MOLLUSCS. 



Nativity. — Spring History and Migration. — Numbers that Light Down. — 

 Egg Laying. — Manner of Egg Laying. — Hatching. — Departure of Locusts. — 

 Destructiveness of Locusts. — How to Combat and Destroy the Locusts. 

 — Nature's Methods of Destroying Locusts. — Invertebrate Enemies. — Ver- 

 tebrate Enemies. — Extent of Locust Invasions. — Probable Future of Locust 

 Depredations — Mollusks. 



NOTHING in the natural history of Nebraska has excited such 

 general interest as the locust question. Where then, do they 

 breed, how frequently do their visitations occur, and what is the 

 amount of damage which they do? 



The migrating locust, (Caloptentts sprelus^) is native to the high 

 and dry regions of the Rocky Mountains. Its permanent habitat 

 is the region between latitude 43 and ^3° north, and 103 and 

 1 14 west of Greenwich. Even some portions of this section are 

 sometimes deserted for a few years for other grounds, but always 

 somewhere within this territory they will be found to exist. In a 

 majority of years some locusts will also be found to breed south of 

 the above line, along the region west of longitude 105 30'. The 



•The reader La referred for a detailed account of the Locust question to the Report of the 

 IT S. Entomological Commission for lh77, which includes the writer's investigations and con- 

 clusions on this subject at greater length and fulness. 



