114 ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



where the Weather Bureau records make available the general facts 

 as to temperature and rainfall. 



Passing, now, from the indoor to some of the outdoor phases of the 

 work, I would say that the field cages covered with 14-mesh wire 

 netting have been of great value. These cages (PI. II, fig. 3) are 

 about 3i feet square by about 4 feet high. The latest type is so con- 

 structed that the top may be removed and the four sides folded flat. 

 This is quite essential where the cages may need to be shipped or 

 moved from one place to another. All fastening to set up the cages 

 and fix the top in place is accomplished by screw hooks and eyes. In 

 one side of the cage is a door about li by 3 feet in size and opening 

 outward. Within there is ample room for the investigator to work. 

 The field cages have been found useful not only in life-history w^ork, 

 but also in remedial work as well. As an illustration of one way in 

 which the outdoor work in the cages proved of great value as supple- 

 menting the observations made in the laboratory, I would describe 

 very briefly the exijeriment made to determine the average number of 

 eggs deposited daily by the average weevil. The first laboratory 

 records obtained indicated that between two and three eggs w^ere 

 de])osited daily by the average weevil. Five females which had begun 

 laying were confined in one of the field cages placed over a plant 

 which had not been attacked by the weevil. The daily observations 

 extending over several weeks showed that these weevils were deposit- 

 ing an average of between -5 and (> eggs a day. This difference in 

 results led to a further investigation, which showed that the rate of 

 egg deposition depended in a considerable measure upon the abun- 

 .dance of squares which had not been attacked, and also that during a 

 period which nuiy be spoken of as the " prime of life " the rate is 

 considerably higher than it is when nearer the end of life. 



Much larger cages than those described have been built at various 

 times for special use in the boll-weevil work. The largest of these 

 is the cage constructed according to plans of Mr. Newell by the 

 Louisiana crop pest commission at Keatchie, La., for the use of Capt. 

 B. W. Marston in making tests of Paris green as a practical insecti- 

 cide for the control of the weevil. This cage covers one- fourteenth 

 of an acre and was originally divided into three sections of equal size 

 by partitions running through the length of the cage. The height 

 of this cage is about 8 feet, and the cost of building it was somewhat 

 over $350. This is probably the largest cage that has ever been con- 

 structed for economic entomological work, and for that reason its 

 size and cost are of especial interest. 



For the purpose of allowing a larger number of hibernation experi- 

 ments this cage has been further divided by cross partitions in each 

 of the original sections into 18 rooms, and here in the various experi- 



