CONTENTS. 



Page. 



lutroduction 9 



( 'onduct of the parasite project 10 



Historical data 11 



Scope of present report 12 



Part I. The status of the cotton boll weevil and its enemies. 



1. A general chronological study of the insect control of the boll weevil. . 13 



2. Nature and sources of the material examined 14 



3. Seasonal studies of insect control, by class of infested material 14 



4. A geographic study of the statistics of insect control 20 



5. A study of the share of insect control in the mortality of immature boll 



weevils 22 



6. A study of how agriculture modifies insect control 30 



7. Climatic considerations 32 



8. How insect control follows the dispersion of the boll weevil 35 



9. The status of the boll weevil and its control by insects 37 



10. A brief statement of the various classes of control exercised upon the 



boll weevil .^. . . 38 



11. Practical conclusions derived from statistical studies 38 



Part II. Biological complex. 



1. A list of the insect enemies of the cotton boll weevil 40 



2. The hosts of boll-weevil parasites 42 



3. Mites which attack the boll weevil 43 



4. Flies which parasitize the boll weevil 47 



5. The hymenopterous parasites of the boll weevil 48 



6. Biological notes upon the parasites of the weevil 54 



7. The development of the parasites 57 



8. The distribution of the parasites ' 61 



9. The parasite seasons 62 



10. Adjustment to new hosts 66 



11. Beetles which prey upon the boll weevil 68 



12. Lepidopterous larvae which are incidentally predatory u})on the boll 



weevil 69 



13. Ants which prey upon the boll weevil 69 



14. Biology of the cohosts of the boll-weevil parasites 73 



15. A list of the host plants of the cohost weevils 80 



16. A summary of the more important biological facts 82 



Part III. The economic application. 



1. The economic principles involved 83 



2. Interpretation of parasite statistics 85 



3. Interpretation of the biological complex 86 



4. How to profit by existing conditions 86 



5. How to plan for the greatest possible control 90 



6. Propagation and artificial introductions 91 



7. Objectionable practices 93 



8. The economic significance of the investigation 94 



Bibliography 97 



5 



