LARGE-CAGE EXPERIMENTS, 190G-7. 



57 



vations have been made. The instruments used are of standard 

 Weather Bureau type (PI. I, fig, 1) and, as the records extend over 

 several years, rehable data have been secured upon the following 

 climatic factors which may affect liibernation : Maximum and mini- 

 mum temperatures supplemented by a continuous temperature 

 record made by a recording thermograph; the actual rainfall as meas- 

 ured in a standard type of rain gauge ; the atmospheric moisture exist- 

 ing at 8 or 9 o'clock a. m. and 5 to 6 o'clock p. m., supplemented by 

 a continuous record of the moisture in the air furnished by a hygro- 

 graph. 



Table XXX. — Outline of hibernation experiments in 1906-7. 



a In this section, 3 bushels of probably infested bolls were exposed, on the surface of the ground in one half 

 of cage, and 3 bushels were buried under 2 inches of dirt in the other half. 



The dates given in Table XXX are the actual dates of beginning 

 the experiment in each locality. The arrangement of the experiments 

 shown in the table is primarily chronological, without regard to the 

 sequence in the number of sections. Some knowledge of the plan of 

 this work is essential to a clear understanding and a correct interpreta- 

 tion of the results obtained from it. 



CLIMATIC CONDITIONS PRODUCING HIBERNATION AND ACTIVITY OF 

 WEEVILS DURING NORMAL HIBERNATION PERIOD. 



The climatic records are started with October 1, 1906, in order 

 to show a comparison between temperature conditions under which 

 weevils are normally very active with those under which they become 

 inactive. The termination of what is considered as being the hiber- 

 nation period is rather arbitrarily set at the time when weevils begin 

 to emerge in considerable numbers. It should be stated that in each 

 locality the climatic records for the winter of 1906 were very unusual. 

 The principal points of variation will be noted in subsequent para- 

 graphs in their most important connections. In each chart (figs. 3-5) 

 showing temperature conditions it has been deemed advisable to 

 show only the line representing the mean average temperature. 



