127 



also was placed a thermometer registering 140° F., which was the 

 highest gradation obtainable. Steam under a pressure of 120 pounds 

 was admitted through a half -inch pipe extending about 2 feet into the 

 car and at about 2 feet from the roof. The temperature outside was 

 about 55° F., with no wind blowing. The treatment was continued 

 for five minutes. 



Upon examination it was found that the thermometer bulb had been 

 shattered; weevils fully exposed were all dead, while those buried in 

 seed were still alive. In another treatment continuing for ten min- 

 utes the weevils buried in the seed were also killed. 



These results indicate that as a general rule cars should be swept 

 fairly clean before the treatment is attempted in order to insure suc- 

 cess. The credit for these experiments belongs to Mr. A. C. Morgan. 



DUKATION OF LIFE OF WEEVILS BURIED AMONG VARIOUS GRAINS, ETC. 



Owing to the fear that weevils will be shipped with grains, experi- 

 ments have been made to determine how long weevils confined motion- 

 less, as the}^ would be when buried in a mass of grain daring warm 

 weather, might survive. The result of this experiment may be com- 

 pared directly with the duration of life of weevils without food bat 

 unconfined (p. 47). 



Table XXXVI. — Duration of life of weevils buried among grains, etc. 





Number 



of 

 weevils 

 tested. 



Character of 

 burial medium. 



Average duration of life. 



Date started. 



Male. 



Female. 





Number. 



Days. 



Number. 



Days. 



1904. 

 June 27 to July 1 



10 



18 



13 



5 



23 



Corn 



5 

 9 

 7 

 3 

 7 

 8 

 15 



3.4 

 2.2 

 1.9 

 3.0 

 2.7 

 3.4 

 6.6 



I 



6 



2 

 8 

 6 



8 



3 4 



June 24 to July 4 



Cotton seed 



2 1 



June 25 to June 28 



3.3 



June 24 



Hay 



3 



June 27 to June 30 



Oats 



3 25 



Julv7 



Rice 



3.0 



April 8 to April 18 



Unconfined 



5 75 







Total 



98 



54 





44 





A verage 



4.0 



3 5 















NATURAL AGENCIES. 



WINDS AND FLOODS. 



Floods and the motion of water along watercourses frequently serve 

 to distribute many weevils along the edge of high -water mark. As 

 river valleys are largely devoted to cotton culture, this wo aid seem to 

 be no small factor in the transportation of weevils. Heav}^ winds 

 earl}^ in the season seem to be of comparatively slight importance, as 

 weevils do not take flight readily when a strong wind is blowing, bat 

 light, warm breezes, sach as prevail throughout the coast country of 



