HIBERNATION. 



99 



per acre in the middle of November. In this connection it is inter- 

 esting to note the progress of entrance into hibernation as shown by 

 Table XXXIV, based on investigations made at Dallas in fields 

 with an average of 8,300 plants per acre. 



Table XXXIV. — Number of boll iveevils per acre upon stalks at different dates at 



Dallas, Tex. 1 



Date. 



Plants 

 exam- 

 ined. 



Living 

 weevils 

 found. 



Living 

 weevils 

 per acre. 



1906. 

 Oct. 12 



110 

 84 

 60 

 35 

 35 

 36 

 35 



35 



122 



190 



106 



29 



27 



10 



5 



3 



9,205 

 18,774 

 14,663 

 6,877 

 6,403 

 2,306 

 1,186 



711 



Oct. 31 to Nov. 3 



Nov. 10 



Nov. 20 



Nov. 22 



Dec. 1 



Dec. 18 



1907. 

 Jan. 21 





i From Bull. 77, Bureau of Entomology, p. 18. 



In connection with this subject we include also Table XXXV for 

 the same period, showing the occurrence of the weevils under shelter 

 on the ground in the cotton fields. 



Table XXXV. — Number of weevils under rubbish on ground at Dallas, Tex. 2 



Field. 



Date ex- 

 amined. 



Portion 



of acre 



examined. 



Weevils 

 found- 



Total 

 per acre. 



Percent- 

 age 

 alive. 



Remarks. 





Alive. 



Dead. 





A 



1906. 

 Nov. '15 



...do 



22 plants. 



1/264 

 1/347 

 1/264 



10/8384 

 10/6236 

 10/8384 



4 



4 



8 

 5 



5 

 1 

 2 









 

 14 



2 



1 

 2 



1,450 



1,056 



2,776 

 5,016 



5,870 

 1,247 

 3,354 



100.0 



100.0 

 100.0 

 26.3 



71.4 

 50.0 

 50.0 



In cracks of ground around bases 



A 



of plants. 

 Under rubbish on ground. 



A 



A 



Nov. 22 

 Dec. 18 



1907. 

 Jan. 11 

 Jan. 29 

 ...do 



Do. 



Do. 



B 



Northeast corner of field. 



c 



Middle of field. 



c 



Near southwestern edge. 



2 This table and the following paragraph are taken from Bull. 77, Bureau of Entomology, p. 20. 



The sum total of weevils found both on plants and on the ground 

 on November 22 shows an average of slightly more than 9,000 weevils 

 per acre, all of which were alive. On December 18 the number that 

 could be accounted for was between 6,000 and 7,000 per acre on the 

 same ground which had been previously examined. On the former 

 date more than two-thirds of the weevils were still upon the plants. 

 On the latter date nearly five-sixths of them were on the ground, and 

 among those on the ground only 26 per cent were living. These fig- 

 ures show that between November 22 and December 18 a very large 

 mortality had occurred among weevils which had entered hiberna- 

 tion, and especially among those which had sought shelter under rub- 

 bish upon the surface of the black-waxy soil of field A. 



