Life history— Continued. Page. 

 The adult — Continued. 



Proportiens of the sexes 92 



. Length of Hfe 92 



Day habits 93 



Night habits 94 



Attraction by Hghts , 95 



Attraction by poisoned sweets 96 



Length of life cycle 97 



Generations of the bollworm 98 



Laboratory experiments .2 99 



Seasonal history 102 



Appearance of spring moths 102 



Progress of infestation by generations 103 



Increase in numbers during the season 104 



Do the adults hibernate? 104 



Insects sometimes mistaken for the bollworm 105 



Predaceous enemies , 107 



Predaceous enemies of the eggs and young larvse 107 



Predaceous enemies of the larger larv?e and moths 109 



Parasites 115 



Parasites of the egg ". 115 



Description of Tricliogramma pretiosa Riley 118 



Description of Telenomus heliothidis Ashmead 119 



Parasites of the larva 119 



Hymenopterous parasites 121 



Description of Microplitis nigripennis Ashmead 122 



Dipterous parasites — Tachinidse 123 



Diseases 124 



Bacterial disease 124 



Scavengers following the bollworm 126 



Methods of bollworm control 127 



Cultural methods ■ 127 



Trap crops 130 



Arsenical poisons 131 



Ineffective methods of combating the bollworm 132 



Mechanical destruction 133 



Methods of bollworm control on corn, tomatoes, and tobacco 133 



Bibliography : 135 



Index 1 151 



