CONTENTS. 



Page. 



Origin and history 15 



Distribution 20 



Losses due to the boll weevil 21 



Indirect losses caused by the boll weevil 26 



Compensation for losses caused by the 1 toll weevil 26 



Prospects 27 



Insects often mistaken for the boll weevil 29 



Food plants of the boll weevil 31 



Life history 32 



Summary 32 



Description 33 



The ee;s; 33 



The larva 33 



The pupa 34 



The adult 34 



Before emergence 34 



Description of adult 35 



Size of weevils 35 



Weight of weevils 35 



Color of weevils 35 



Secondary sexual characters 37 



Seasonal history 38 



The adult weevil 38 



Emergence 38 



Changes after emergence 38 



Protective habits 38 



Food habits 38 



Ability to locate cotton 41 



Feeding habits of hibernated weevils 41 



Destructive power by feeding 42 



Attractiveness of various substances 42 



Sense of color 43 



Movements on food plant 43 



Effects upon squares and bolls of feeding by the boll weevil 44 



Susceptibility of various cottons 45 



Duration of life of adult weevils 47 



Cannibalism 50 



Seasonal proportion of sexes 51 



Fertilization 52 



Age at 1 leginning of copulation 52 



Sexual attraction and duration of copulation 52 



Duration of fertility 52 



Parthenogenesis 53 



Oviposition 53 



Age at 1 leginning of oviposition 53 



Examination of squares before oviposition 54 



Selection of uninfested squares for oviposition 54 



Dependence of reproduction upon food obtained from squares 55 



Place of egg deposition 56 



The act of oviposition 56 



Time required to deposit an egg 58 



Stimulating effect of abundance of squares upon egg deposition. . 58 



Activity of weevils in different parts of the day 58 



Seasonal rate of oviposition 59 



Is the fecundity of the weevil decreasing? 60 



Period of oviposition 61 



Effects of oviposition upon squares 61 



Probable original breeding habit 62 



9 



