IV TABLE OF CONTENTS. 



CHAPTER IV. 



Page. 

 Agricultural bearing of the locust problem 123 



Drawback to the settling of the West, 124 — Wha.t is likely to he the efifect 

 in the future, 125 — Modification and settlement of the Western plains, 

 129 — Crops which suffer most, and those which suffer least, 130 — Small 

 grains not affected by invading swarms, 128 —Need of judgment in plant- 

 ing, 129. 



CHAPTER V. 



Permanent breeding-grounds of the rocky mountain locust 131 



Permanent breeding-grounds, 131 — Definition of the permanent region, 133— 

 Its character and extent, 134 — The Rocky Mountain locust a sub-boreal 

 insect, 135 — The Sub-permanent region, 136 — The Temporary region, 136. 



CHAPTER VI. 



Geographical distribution 136 



Eastern limits of spread, 137 — Northern limits, 139 — Western limits, 140 — 

 Southern limits, 141 — Sub-permanent region, 142. 



CHAPTER VII. 



Migrations 143 



Classification of flights, 143— Invading swarms, 143 — Returning swarms, 

 143— Local flights, 143 — Height at which swarms move, 144 — Effect of 

 change of wind and weather on flights, 145 — Flight at night, 147 — Migra- 

 tions previous to 1877 east of the Rocky Mountain plateau, 148 — Direction 

 of invading swarms prior to 1877, 149 — Direction of flight in 1876, 151 — 

 Migrations within the permanent region, 153-158 — in Montana, 153 — in 

 Wyoming, 156 — in Colorado, 157 — in Eastern Idaho and Utah, 158— in the 

 lower Snake Valley, 158 — Return migrations from the temporary region 

 previous to 1877, 159-162— Return migrations in 1877, 162-165 — Local 

 flights in 1877, 165— Record of flights for July 3 and July 20, 1877, 165- 

 169— Summary of flights by States, 170-174— Southward flights in 1877, 

 175 — Movements in different directions at one time, 176 — Destination of 

 return swarms, 177. 



CHAPTER VIIL 



Habits and natural history 212 



Destructive powers of locusts, 212-215 — Stoppage of railroad trains, 215 — 

 Rate at which locust swarms move, 215 — Velocity of flight, 216 — Direction 

 of invading swarms, 217 — Time of appearance of invading swarms, 217 — 

 Flight at night, 218— Height of flight, 219— General habits at night, 219— 

 Where the eggs are laid, 222 — Manner in which the eggs are laid, 223 — 

 Philosophy of the egg-mass, 225 — The female lays more than one egg-mass, 

 226 — Interval between different egg-layings, 227 — Number of eggs laid, 

 228— The hatching process, 228-231 — Where and under what conditions of 

 soil the young batch most freely, 231 — Time of hatching, 231 — Habits of 

 the young or unfledged locubts in the temporary region, 232 — Directions 

 in which the young travel, 234 — Rate at which the young travel, 235 — 

 They reach but a few miles east of where they hatch, 235 — Not led by kings 

 and queens, 236 — Time of year when wings are acquired, 237 — Direction 

 taken by swarms deimrtiug from the Temi^orary region, 238— Destination 

 of departing swarms, 238 — Do the return swarms breed ? 239 — Do return 



