4 



Contents. 



CHAPTER III. 



PAGE 



Native Home and Geographical Range of the 



Species East of the Mountains 55 



Source of the devastating swarms that reach into the 

 Mississippi Valley, 55. — Their origin in the extreme North- 

 west country lying east of the mountains, 56. — Cause of 

 their emigration, 57. — Difference between summer and fall 

 swarms, 58. — The species not at home in the Mississippi 

 Valley, 62. — Not permanent or able to perpetuate itself 

 there, 62. — Conditions which prevent such permanence, 

 63. — Not likely to do serious harm east of the ninety- 

 fourth meridian, 65. — Reasons why, 65. 



CHAPTER IV. 



Natural History and Transformations . . . . 69 



How the eggs are laid, 69. — Philosophy of the egg-mass, 

 71. — The female capable of laying more than one egg- 

 mass, 72. — The escape of the young locust from the egg, 

 73. — Its emergence from the ground, 78. — Growth and 

 transformations, 78. — Acquisition of wings, 80. — Number 

 of molts, 82.— Flight at night, 83. 



CHAPTER V. 



Habits, and Power for Injury 85 



Flight and ravages, 85. — Migratory instinct and great de- 

 structive power confined to a single species west of the 

 Mississippi, 88. — Food plants, 89. — Injury to fruit trees, 

 93. — Time of appearance of invading swarms, 94. — Rate 

 at which they spread, 95. — Direction of their flight, 96. — 

 Where the eggs are preferably laid, 96. — Time of hatching, 

 97. — Habits of the young or unfledged locusts, 98. — Direc- 

 tions in which the young travel, 100. — Rate at which 

 they travel, 100. — Limit of their eastward spread, 100. — 

 Not led by kings or queens, 101. — Direction taken by the 

 departing swarms, 103. — Their destination, 104. 



CHAPTER VI. 



Effects of the Young Insects in the Country 

 where they hatch, but where they are not 

 indigenous 107 



Experience with the young locusts in spring, 107. — Contrast 

 in summer and fall, 108. — No evil without some compen- 



