LARGE-CAGE EXPERIMENTS, KEATCHIE, LA., 1905-6. 



43 



Table XIX. — Comparison of emergence records at Keatchie, La., for u'ccvils collected 

 in Louisiana luith those collected in Texas. 



Altogether in these sections 110 of the Louisiana weevils and 173 of 

 the Texas weevils emerged, making a percentage of total survival in 

 the former case of 1.77 and in the latter case of 2.62. On the w^hole 

 the Texas weevils emerged slightly earlier than did those collected in 

 Louisiana, but the records are too nearly similar to indicate that such 

 would regularly be the case. 



RELATION OF EMERGENCE TO EFFECTIVE TEMPERATURES. 



The practical point in these studies of temperature and emergence 

 relationships is to ascertain the facts upon which emergence depends, 

 so that it may be possible from a study of temperature records for any 

 locality to form fairly reliable conclusions as to the effects which those 

 temperature conditions may have had upon weevil activity. In this 

 way it may be possible to determine approximately the time when 

 weevil emergence begins, the time when the majority of weevils will 

 probably have left their hibernation quarters, and approximately the 

 time at which emergence becomes complete. In this connection it 

 will be profitable to compare the records for Dallas, Tex., with those 

 for Keatchie, La., for the same periods. 



The total effective temperature is obtained by computing the sum 

 of the mean average effective temperatures for each of the days 

 included within the period shown. For example, if the mean average 

 temperature for the first day of a period is 60° and for the second day 

 68°, the average effective temperature for the two days is 17° and 25°, 

 respectively. The sum of these, or 42°, is the total effective temper- 

 ature for those two dates. 



