105 



DURATION OF HIBERNATION PERIOD. 



As the observations upon this point have nearly all been made at 

 Victoria, Tex., the statements made refer especially to that locality. 

 It must be borne in mind that latitude and altitude, as well as seasonal 

 variations, will influence the limits of this period. In general, how- 

 ever, it may be said that hibernation begins at about the time of the 

 first hard frost, and that it continues until the mean average tempera- 

 ture has been for some time above 65° F. In the spring of 1903 

 weevils left hibernation quarters at Victoria only when the mean aver- 

 age temperature had been for some time at about 68° F. While it is 

 true that weevils if disturbed in hibernation are active at much lower 

 temperatures than this, for some reason they do not leave the shelter 

 of their hibernation places. 



At Victoria, Tex., the average hibernation season may be said to 

 extend from about December 1 to about April 1, or a period of about 

 4 months. In the spring of 1904 weevils began coming from hiber- 

 nation by the middle of March and it is certain that the last had not 

 emerged by the middle of May. In more northern latitudes hiberna- 

 tion will, as a rule, begin earlier and last later, covering a period of 

 from 4 to 5 months. 



APPARENTLY FAVORABLE CONDITIONS FOR HIBERNATION. 



In December, 1902, a series of experiments was started to test the 

 influence of various conditions upon the successful hibernation of 

 weevils. Owing to the writer's absence from Victoria examinations 

 could not be made at intervals, as would have been desirable. But at 

 the middle of April, 1903, careful examinations were made to ascer- 

 tain the shelter in which live weevils were found. In the preparation 

 of hibernation jars several inches of dirt were placed at the bottom, and 

 above that a variety of such rubbish as was thought might tempt the 

 weevils to shelter. Dead banana leaves, hay, cotton leaves, dry bolls, 

 squares, etc., were among the things used as rubbish. As several of 

 these were placed in each jar the weevils had an opportunity to choose 

 their shelter. Among the 39 which lived through the winter, 19 were 

 found in the banana leaves, 7 in hay, 5 in dry cotton leaves, 4 were 

 buried in dirt, 3 were on the surface of the soil, and 1 was hiding in 

 an open boll. It appears, therefore, that 31, or 80 per cent of the 39 

 live weevils, were found in what may be termed " leaf rubbish." It 

 was noted also that 25 of the survivors passed the winter out of doors 

 in various locations, while 13 were under shelter indoors. Of the 

 weevils placed out of doors all but one lot were protected from the 

 rain. The 15 weevils contained in the jar which became wet all died, 

 while but few of the jars which were dry failed to show a live weevil 

 in the spring. Leaf rubbish and dryness appear to be favorable fac- 

 tors in successful hibernation. 



