224 BIBLIOGRAPHY OF ECONOMIC ENTOMOLOGY. 



1643. EILEY, C. V. Continued. 



CHAPTER V: By A. S. Pachard, jr. 



Permanent breeding-grounds of the Rocky Mountain locust 131 



Permanent breeding-grounds, 131 Definition of the permanent re- 

 gion, 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: By C. Thomas and A. S. Pachard, jr. 



Geographical distribution 136 



Eastern limits of spread, 137 Northern limits, 139 Western lim- 

 its, 140 Southern limits, 141 Sub-permanent region, 142. 



CHAPTER VII: By A. S. Pachard, jr., and C. Thomas. 



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 Migrations 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 VIII: By C. V. Riley. 



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 Inter- 

 val between different egg-layings, 227 Number of eggs laid, 

 228 The hatching process, 228-231 Where and under what con- 

 ditions of soil the young hatch most freely, 231 Time of hatch- 

 ing, 231 Habits of the young or unfledged locusts in the tem- 

 porary 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 departing from the temporary region, 238 Destination 

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

 return swarms from the temporary region retrace their course T 

 240 The species essentially single-brooded, 240-243 Reasons 

 why it cannot produce two generations annually, 243 The spe- 

 cies can not permanently dwell in the temporary region, 244 

 The insects which hatch there do not remain, 246 Extensive and 

 thick egg-laying seldom occurs twice consecutively in the same 

 locality, 247 Reasons why it does not, 248 Causes of migration, 

 249 -Food-plants, 251 Crops and plants most liked and those 

 feast liked, 252-254 Unnecessary alarm caused by compara- 

 tively harmless species, 255. 



