EMEKGENCE FEOM HIBEENATION, 1907. 



73 



The unprecedented emergence during March is very easily explained 

 by the remarkable temperature conditions during that month. In 

 spite of the fact that emergence began earlier than had ever been 

 known previously, it continued later also because of the exceptionally 

 low temperatures prevailing during April, May, and June. A com- 

 parison of figures 1 and 2 w^ith figures 6 to 8 is interesting and shows 

 how strikingly the nature of the emergence movement may vary in 

 respect to difi'erence in climatic conditions. The careful examina- 

 tions made to discover the termination of the emergence period were 

 continued for fully two weeks after the last weevil was found. It 

 seems impossible to explain the long-delayed emergence of some 

 individuals. The lack of an explanation, however, does not alter the 

 fact that emergence is probably not generally complete until after the 

 middle of June. 



Table XXXVI. — General summary of experiments of 1906-7 on emergence from 



hibernation. 



Locality. 



Number of 

 weevils — 



Putin 

 cages. 



Used as 

 basis for 

 percent- 

 age of 

 emer- 

 gence.o 



Number 

 of wee- 

 vils 

 emer- 

 ging 



Percent- 



emer- 

 ging- 



Dallas, Tex... 

 Calvert, Tex. . 

 Victoria, Tex. 



32,439 

 20,430 

 23,645 



30,864 

 19,408 

 22, 463 



3,464 



1,842 



6 3, 026 



11.22 

 9.49 

 13.47 



Total and average . 



76, 514 



72,735 



8, 332 



11.45 



oBasis for computing the percentage of emergence is 5 per cent less than the number of weevils put in 

 cages owing to the escape of some weevils through the meshes of the wire. 

 b Two weevils not in summary. 



A deduction of 5 per cent from the number of weevils placed in the 

 hibernation experiments is made to furnish a more correct basis for 

 determining percentages, on account of the fact that experiments 

 have shown that about 5 per cent of a miscellaneous collection of 

 w^eevils may be able to escape through 14-mesh wire (PL VII, fig. 1), 

 such as was used in the construction of these cages. The percentage 

 of survival is strikingly similar in each locality. The average sur- 

 viving hibernation — approximately 11 per cent — is probably the 

 highest that has ever occurred since the weevil entered Texas. 

 Although observations have indicated that occasionally the per- 

 centage of survival may be as high as this in the field, it is fortunate 

 for the cotton planter that such is very rarely the case. 



