COTTON BOLL WEEVIL IN THE MISSISSIPPI VALLEY. 



25 



This period in the 1914 studies varied from 22 days to death on the 

 same day that the last egg was deposited, with an average of 3.4 

 days. Death on the last day of deposition was observed five times 

 during the season. 



ACTIVITY OF FEMALES IN DIFFERENT PARTS OF THE DAY. 



Early in August, 1914, two tests were conducted to determine the 

 egg-laying activity of the females during the different parts of the 

 day. Nine actively depositing females were used in each test. The 

 results are shown in Table XX. 



Table XX. — Periodic division of oviposition of boll weevils. 



FIRST TEST: AUGUST 4 AND 5. 







Percent- 



Length of period. 



Total 

 eggs 

 laid. 



age of 

 total ovi- 

 position 

 in each 

 period. 







Per cent. 



5 a. m. to 9 a. m... 



16 



12.8 



9 a. m. to 1 p. m . . 



47 



37.6 



1 p. m. to 5 p. m. . 



29 



23.2 



5 p. m. to 8 p.m.. 



23 



18.4 



8 p. m. to 5 a. m. . 



10 



8.0 



Maxi- 

 mum 



tempera- 

 ture. 



SECOND TEST: AUGUST 7 AND 8. 



Dawn 



Morning . . 

 Afternoon. 

 Evening. . 

 Night 



5 a. m. to 9 a. m. 

 9 a. m. to 1 p. m. 

 1 p. m. to 5 p. m. 

 5 p. m. to 8 p. m. 

 8 p. m. to 5 a. m. 



8 



9.1 



27 



30.7 



39 



44.3 



10 



11.4 



4 



4.5 



summary: both tests. 



Dawn 



Morning . . 

 Afternoon. 

 Evening . . 

 Night 



5 a. m. to 9 a.m.. 

 9 a. m. to 1 p. m. 

 lp. m. to 5 p. m. 

 5 p. m. to 8 p. m. 

 8 p. m. to 5 a. m. 



- 24 



11.3 



74 



34.7 



68 



31.9 



33 



15.5 



14 



6.6 



From this table it is seen that in the first test the greatest activity 

 was exhibited in the morning period and the afternoon period ranked 

 second, while in the second test the afternoon period was highest and 

 the morning period was second. In both cases the night was the 

 lowest of all. 



The only other test of this sort which has been conducted was at 

 Tallulah during 1910 when it was found that the afternoon period 

 ranked first and the evening period was second. However, this test 

 was conducted during July and the one this year was in August, so 

 the results are not strictly comparable owing to differences in the light 

 and temperature conditions during the various periods. 



