Page 



Development 92 



Percentage of weevils developed from infested squares 92 



Development of weevils in squares which never fall 92 



Duration of the life cycle 93 



Broods or generations 95 



Possible annual progeny of one pair of hibernated weevils ... - 97 



Thermal influence upon activity and development 98 



Influence of retarded development upon sex 100 



Laboratory experiment in effect of temperature upon locomotive activity. 101 



Gradual development during hibernation in south Texas 102 



Seasonal history 103 



Hibernation 103 



Entrance into hibernation 103 



Shelter sought in hibernation 104 



Duration of hibernation period. 105 



Apparently favorable conditions for hibernation 105 



Percentage of weevils hibernating successfully 106 



Time of emergence from hibernation 106 



Gradual emergence from hibernation 107 



Distance hibernated weevils will fly to food 108 



Gradual attraction of hibernated weevils to squares 109 



General movement of hibernated weevils in field having considerable 



seppa cotton 110 



Apparent dependence of reproduction upon food obtained from squares. 112 



Progress of infestation in fields 113 



Weevil injury v. square production 116 



Effect of maximum infestation upon weevil multiplication 119 



Proportion of squares attacked that are not destroyed 1 20 



Relation of weevils to "top crop" , 120 



Some reasons for the early destruction of stalks 121 



Dissemination 123 



Artificial agencies 123 



Weevils in seed houses at ginneries 124 



Gin agency at border line^of infested territory 124 



Dissemination through shipment of seed cotton and cotton seed 125 



Treatment of seed for shipment 126 



Duration of life of weevils buried among various grains, etc 127 



Natural agencies 127 



Winds and floods „ . . . . 127 



Migration 128 



Effect of defoliation upon weevil movement 130 



Natural control 1 32 



Mechanical control 132 



Pilosity of plant obstructing weevil movement 132 



Proliferation and its effect in bolls and squares 133 



Climatic control 134 



Temperature endured by weevil larvse in squares exposed to sunshine. 135 



Temperature endured by weevil stages in winter 136 



Effect of rains upon development of weevils 137 



Effect of wet winter weather on hibernating weevils 138 



Effect of overflows in fields 138 



