110 



weevils, to find how rapidly they became concentrated upon plants bear- 

 ing squares. At the time of beginning the observations no plants had 

 begun to form squares. The first squares were observed upon several 

 plants on April 15, and the first eggs were found deposited in squares 

 on April 26. These plants were thickly scattered through the field, 

 and consequently the distances through which they would exert an 

 attractive influence upon the weevils could not have been great. (PL 

 XVII, ^g. 74.) 



Upon May 9 to 11, between three and four weeks after squares had 

 begun to form, a complete examination was made of all plants grow- 

 ing upon an area of about three acres, and a census was taken to deter- 

 mine the number of weevils present, the number of plants bearing 

 squares, and the proportion of weevils found upon plants with and 

 without squares. In this examination 857 plants were carefully exam- 

 ined. At that time 32.5 per cent of this total number were bearing 

 squares which were large enough to be attractive to the weevils if they 

 were seeking squares for oviposition. Upon the first 45 rows, which 

 were not quite so far advanced as in other portions, 22 per cent of 451 

 plants had squares; upon these rows 61 per cent of the 159 weevils 

 taken were found upon 51 plants bearing squares, and 39 per cent 

 were found upon 51 plants not having squares. In the next 21 rows, 

 which were considerably more advanced in growth, among 406 plants 

 43 per cent had squares, and these plants had at that time 94 per cent 

 of the weevils found, while the 57 per cent of plants without squares 

 had only 6 per cent of the weevils found. 



An exact idea of the relative condition of the seppa and planted cot- 

 ton upon the dates April 16 and May 14 may be obtained by reference 

 to Plate XVII, figures 73 and 74. Upon the latter date the planted 

 cotton had, upon the average, six to eight leaves and no squares, while 

 one-third of all the seppa plants examined had squares, many of which 

 were fully four weeks old. In spite of the fact that much of the cot- 

 ton had been in so attractive a condition for so long a time, these plants 

 had attracted only three-fourths of those weevils which were found in 

 their immediate vicinity. From these facts it seems safe to conclude 

 that even under the most favorable conditions the inefficiency of trap 

 rows or trap plants has been demonstrated. 



GENERAL MOVEMENT OF HIBERNATED WEEVILS IN FIELD HAVING 

 CONSIDERABLE SEPPA COTTON. 



Beginning esirly in April, 1904, a series of observations was under- 

 taken to show the general direction and distance of the movement of 

 hibernated weevils in a field before the planted cotton was in condi- 

 tion to attract them as food. At the middle of April all seppa plants 

 in a field of 65 acres were destroyed, except those growing on two 

 plots — one 4 acres and the other about 3 acres in extent. These 

 plots were located upon the southern edge of the field. The general 



