IN I i; \.\ci. into EIBERNATION. If) 



TIME OF ENTERING HIBERNATION. 



Before discussing the question of tin* time a1 which weevils usually 

 " enter hibernation" it seems desirable to explain the sense in which 

 thai term is used. The action of the weevils in securing shelter from 

 approaching cold is not intelligent. It is probably true that they 

 have n»' such sense of sight as we commonly understand Prom the 

 use of thai word and that their selection of shelter is uot at all 

 guided by that sense. We mean by this that a weevil on a cotton 

 plant can not see at any distance shelter winch might l>e attractive 

 to it ami thereupon fly from t lie plant to the shelter. It is true that 

 eold nights with a temperature between lo and 50 K. succeeded 

 l>\ warm still days, such as occur commonly in the Pall, do seem to 

 stimulate" the weevils to an unusual activity both in flight and in 

 crawling. It may be true that they have an instinctive knowledge 

 o\' the approach of temperature conditions from which they must 

 secure shelter, but it is also true that manj weevils remain active 

 upon plants Por some time after the plants have been destroyed by 

 Prost and frequently until several weeks after other individuals 

 have entered hibernation. In speaking of entering hibernation, 

 therefore, we mean the entrance of the weevils upon a period of 

 comparative if not complete inactivity. Their action in. securing 

 shelter is gradual and governed primarily by the degree of protec- 

 tion from the cold which they may receive. If early in the season 

 a weevil accidentally finds shelter which gives it exceptional pro- 

 tection Prom the cold it will likewise be exceptionally protected from 

 heat, and therefore less likely than are other less fortunate 1 indi- 

 viduals to resume'its activity upon warm days. If at first the 

 shelter which weevils find is hut slight, they will be easily influenced 

 1>\ succeeding warmth, and in another period of activity will be 

 likely to find better protection. Their flight upon warm days un- 

 doubtedly leaves large numbers of them outside of the cotton fields, 

 where they are as likely to find favorable shelter as within the fields 

 themselves. 



From this explanation it will be understood that it is rarely pos- 

 sible to indicate by a single date the time when weevils enter hiber- 

 nation. It may be better expressed as a period within the limits 

 of which a large majority, though possibly not all, weevils may seek 

 shelter. Naturally this time varies according to the seasonal tem- 

 perature conditions, so that in one locality it may occur several 

 weeks earlier in one season than in another. It is also evident that 

 differences in temperature conditions due to latitude or altitude will 

 cause a similar variation in the time when weevils enter hibernation. 

 In the following paragraph are given the approximate dates which 

 have been determined Por this event at various localities since L902. 



