14 



BULLETIN 1328, IT. S. DEPARTMENT OP AGRICULTURE 



INFLUENCE OF STORMS AND RAIN 



The period of the season of 1922 in which these data were obtained 

 included many bright days on which storms occurred during the 

 course of the afternoon, giving an excellent opportunity to study the 

 behavior of the bees on the approach of a storm; in fact, for the 

 purposes of a brief general study of flight activities, there were 

 too many such days. 



The influence of a storm is well shown by the data for a single day 

 (Table 3, and fig 4.) The records on which this curve is based were 



/oo \ 



Fig. 4. — Flight, temperature and hive-weight data for May 15, 1922, showing 

 the effect of a threatened storm (2.30-4.15 p. m.) on nights 



taken on May 15, a bright, sunny day until the afternoon. The 

 following chronological data show the weather conditions : 



Time Weather conditions 



2.30 A clouding over is noticed. 



2.45 The very much darkened sky indicates the sudden approach of a 

 storm. 



3.00 It is thundering, and an increase in the number of heavily laden 

 nectar-carrying bees is noted at the gates. 



3.15 A gusty wind is blowing, precipitation being expected any minute. 



3.30 The storm is passing from a westerly direction to a southerly. The 

 very dark nucleus of the storm, where precipitation appears to be tak- 

 ing place, is from 3 to 4 miles away. 



3.45 The air is calmer, the storm having passed without any precipitation. 



4.00 The sun is shining occasionally and for short intervals. 



4.15 The sun is shining steadily, and it has cleared up completely. [This 

 condition continued for the remainder of the day.] 



No better example of the sudden approach of a storm with all its 

 symptoms to the very point of precipitation, but without actual pre- 

 cipitation, could have been obtained. 



