PINK BOLLWORM OF COTTON IN MEXICO. 



41 



over, larvae removed from all seed and lint were placed in screened 

 boxes and flowerpots and allowed to enter the soil. These were also 

 buried flush with the surface of the ground. A sample of the bolls 

 used was examined at the time and found to contain an average of 

 6.64 fourth-instar and 0.03 third-instar larvae per boll. The material 

 was examined at different dates and the results are given in Table XXI. 



Table XXI. — The mortality among hibernating Pectinophora gossypiella larvae under 



different field conditions. 



Ex- 



Conditions of exposure. 



Examination. 





ment 



No. 



Date. 



Live 



larvse. 



Dead 



larvae. 



Live 

 pupae. 



Pupal 

 skins. 



Remarks. 



557 



300 larvae removed 

 from seed and lint 

 and buried in wood- 

 en box of soil in 

 irrigated plot. 



50 larvae in flowerpot, 

 same as 557. 



1919. 

 June 11. 



May 10.. 















 

 



12 



28 





 6 





 

 

 

 39 

 20 

 74 

 51 



52 

 13 

 



68 



54 



83 



152 











2 



Several. 



3 

 

 













 

 



3 



1 





 1 





 

 

 

 



1 



2 

 6 





 2 

 





 

 

 2 

 

 













 

 



2 



1 





 3 





 

 



10 

 

 3 

 2 



18 





 10 

 





 

 6 

 11 



7 

 



61 empty dirt cells 

 around side of box. 



558A 





558c 



June 10. . 

 June 11.. 

 June 11.. 



June 12.. 

 May 10.. 







558b 









558d 



50 double seeds buried 

 in flowerpot on irri- 

 gated plot. 



300 larvae removed 

 from seed and lint 

 and buried in wooden 

 box of soil in nonirri- 

 gated plot. 



50 larvae in flowerpot, 

 same as 560. 







560 





I^arvae webbed up on 

 side of box. 



561A 





1 



7 



561b 



June 11.. 

 June 12.. 



Mar. 10 



bolls). 

 Apr. 24 



bolls). 

 May 16 



bolls). 

 June 6 



bolls). 

 Mar. 10 



bolls). 

 Apr. 24 



bolls). 

 May 15 



bolls). 

 June 4 



bolls). 



Mar. 11 

 bolls). 



Apr. 24 

 bolls). 



June 7 

 bolls). 



Mar. 11 



bolls). 

 Apr. 24 



bolls). 

 May 15 



bolls). 

 June 7 



bolls). 

 July 25 



bolls). 

 Aug. 22 



bolls). 







561c 



50 double seeds in flow- 

 erpot on nonirrigated 

 plot. 



200 green and dry bolls 

 buried li to 7 inches 

 deep on irrigated 

 plot. 



200 green and dry bolls 

 left on top of ground 

 on irrigated plot. 



200 green and dry bolls 

 buried in soil 6 to 7 

 inches deep on non- 

 irrigated plot. 



200 green and dry bolls 

 left on top of ground 

 on nonirrigated plot. 







559a 



(10 

 (10 

 (50 



(130 

 (10 

 (10 

 (50 



(116 



(10 



(10 



(180 



(10 

 (10 

 (50 

 (50 

 (25 

 (80 



65 

 48 



Bolls rotting badly. 



Very rotten and fallen 



to pieces. 

 Fallen to pieces. 







559B 



562A 

 562b 



29 

 36 

 194 

 344 







13 







26 



28 

 137 

 188 

 100 

 



to pick from soil. 

 Bolls in good condi- 

 tion. 

 Do. 



Some of bolls getting 

 rotten, but those 

 which had opened 

 when experiment be- 

 gan still in good con- 

 dition. 



Bolls badly rotted. 



Badly rotted and could 



not separate bolls. 

 Thoroughly rotten. 



Bolls in very good con- 

 dition. 

 Do. 



Do. 



Do. 



Do. 



Do. 



