14 



was necessary to pay particular attention to the immediate economic 

 phases of the problem', and a detailed study of the habits of the insect 

 was impossible. In 1902, by the aid of a special appropriation by 

 Congress, it became possible to establish a complete field laboratory 

 in the portion of Texas in which the weevil had been known to exist 

 at that time for about eight years, where a careful investigation could 

 be conducted regarding the points in the life history of the pest that 

 offered even remote chances of suggesting means of avoiding damage. 

 The results of the work at this laborator}^ that have been of more 

 immediate economic bearing have already been published in farmers' 

 bulletins of this Department. However, as will be seen from the fol- 

 lowing pages, a very large mass of information concerning ail the 

 habits of the boll weevil has been accumulated. Not only on account 

 of the great economic importance of the problem and the demand for 

 information from numerous quarters concerning the biology of the 

 pest, but also on account of the fact that the methods followed in this 

 work have been to some extent original, and may be of use in con- 

 nection with the investigation of other insects, it is thought advisable 

 to publish a great number of the observations that have been made. 

 The historical and economic features, to which reference has been 

 made elsewhere in the publications of the Bureau, are included to 

 bring together in convenient form practical!}^ all that is known regard- 

 ing the species. Much information obtained by the earlier investi- 

 gators of the Division of Entomology, Dr. L. O. Howard, Mr. C. L. 

 Marlatt, Mr. C. H. T. Townsend, and Mr. E. A. Schwarz, has been 

 used. On account of the painstaking character of the work of Mr. 

 Schwarz, and his intimate knowledge of related species, his reports, 

 largely unpublished, have been found especially valuable. Special 

 acknowledgment is due to Mr. Schwai^ also for his assistance in the 

 determination of the recognizable insect fragments contained in the 

 bird stomachs collected and examined. Because of his ver}^ intimate 

 knowledge of this work he has written the paragraphs under the sub- 

 ject -'Birds," pp. 150 to 153. 



\ In presenting this work the authors have taken care to state fully 

 the data furnishing the basis for the various conclusions. Under each 

 important heading will be found, first, a description of the methods 

 and apparatus employed; second, a full and in many cases tabular 

 statement of observations; third, the obvious conclusions. Care has 

 constanth^ been exercised to avoid errors likely to result from artificial 

 conditions in the laboratory. A large part of the work of the past 

 two years was in ascertaining how closely laboratory results corre- 

 sponded to the actual conditions in the field. The writers have on 

 man}" occasions been surprised to discover how close the correspondence 

 is, and consider that the demonstration on a large scale of the possibil- 

 ity of accurately determining the details of the life history and habits 



