82 



HIBERNATION OF THE COTTON BOLL WEEVIL. 



Table XLII. — Weekly summary of emergence records, showing relation to effective tem- 

 perat^ires, 1907 — Continued. 



Total emergence: 



Calvert 1, 842 



Dallas 3,464 



Victoria 3, 026 



Grand total ' 8,332 



The large percentage of total emergence occurring during the first 

 week of March is very striking and unquestionably also very excep- 

 tional. Only the extremely high range in temperature can explain 

 this unusual record. Taking the average of the three locations, 

 practically one-fourth of the total emergence occurred during the 

 first week of March. During the following two weeks more than 

 another one-fourth also emergetl. During this period the tempera- 

 tures averaged as high as they do ordinarily in May; and owing to 

 the fact that a considerable majority of weevils had left shelter 

 before the end of March the number emerging after that time shows 

 a marked decrease. 



It must not be supposed that these statements represent anything 

 like usual conditions, although they unquestionably represent the 

 facts in regard to emergence in 1907. The comparison of these 

 records with those for Dallas and Keatchie (see p. 44) in 1906 will 

 sliow clearly the exceptional nature of the variation. 



It should be stated that when the emergence takes place as rapidly 

 as was the case in March, 1907, the actual number of Hving weevils 

 in the field may be expected to increase for some time because of the 

 fact that a larger number of weevils is added to the total living on 

 account of continued emergence than is lost on account of death 

 among weevils which have previously emerged. 



