32 
BULLETIN 1328, TJ. S. DEPARTMENT OF AGRICULTURE 
necessity of a shortening of the voyages as dusk approaches is 
apparent, but the cause of the short A^oyages at the beginning of the 
day's flight is problematical. It may be that these short trips in the 
dearth are those made by the water carriers. 
The flights which occurred on May 9 (fig. 13) when locust honey 
was available, were intermediate between those given aboA^e, their 
average duration in the period of equilibrium being 42 minutes. 
The bees were obliged to travel a considerable distance. The details 
of the variation for this day are easily interpreted from the figure, 
and need not be explained in full. The method of interpretation is 
the same as for the examples gi^^en above. 
These data also indicate that when conditions for a maximum 
secretion of nectar occur, enabling the bees to gather their loads 
rapidly and return quickly to the hive, there are relatively more bees 
within the hive. The significance of this fact with reference to 
swarming is apparent. 
A LIMIT TO THE NUMBER OF TRIPS AND THE TIME SPENT 
WITHIN THE HIVE 
To determine the number of trips which the bees of a colony of 
honeybees make in the course of any particular day, it is necessary 
to know the total number of exits (or returns) for the day and the 
total number of bees which are participating in the flight on this 
day. Owing to the limited time available for this investigation, no 
attempt was made to manipulate the colony periodically so as to 
take a census of the field bees. With the figures available, however, 
a lower limit to the number of bees participating in the flight is 
given by the average number of bees in the field, giving in turn an 
upper limit to the number of trips each bee could make. For 
example. May 15 (9.45 to 3) the average number in the field is 
1,567, so that during this period each bee could not make as many 
as 32,492-f-l,567=20.T4 trips, for to maintain this rate these 1,567 
bees would have to go in and then out of the hive immediately. 
Table 4. — Record of exits and returns, total and per quarter hour, and of bees 
in the field, July 10, 1922 
Bees 
Exits 
Returns 
Bees 
in 
Exits 
Returns 
Total 
Total 
in one- 
in one- 
Time 
Total 
Total 
in one- 
in one- 
Time 
exits 
returns 
in 
field 
f ourth 
fourth 
exits 
returns 
field 
fourth 
fourth 
hour 
hour 
hour 
hour 
Number 
Number 
Number 
Number 
Nmnber 
Number 
5.30 





10.15 
3,674 
1,513 
2,161 
434 
203 
6.45 
4 
2 
2 
4 
2 
10.30 
4,699 
1,946 
2,753 
1,025 
433 
6.00 
18 
11 
7 
14 
9 
10.45 
5, 212 
2,201 
3,011 
513 
255 
6. 15 
32 
19 
13 
14 
8 
11.00 
5,610 
2,595 
3,015 
398 
394 
6.30 
46 
31 
15 
14 
12 
11.15 
5, 965 
2,981 
2,984 
355 
386 
6.45 
63 
41 
22 
17 
10 
11.30 
6, 600 
3,349 
3,251 
635 
368 
7.00 
160 
73 
87 
97 
32 
11.45 
6,971 
3,613 
3. 358 
371 
264 
7. 15 
225 
147 
78 
65 
74 
12.00 
7,381 
4,133 
3,248 
410 
520 
7.30 
332 
219 
113 
107 
72 
12. 15 
7,930 
4,792 
3,138 
549 
659 
7.45 
398 
269 
129 
66 
50 
12.30 
8, 469 
5,117 
3,352 
539 
325 
8.00 
503 
360 
143 
105 
91 
12. 45 
9,242 
5, 646 
3,596 
773 
529 
8. 15 
612 
438 
174 
109 
78 
1.00 
9, 662 
6,134 
3, 528 
420 
488 
8.30 
770 
525 
245 
158 
87 
1. 15 
10. 197 
6,692 
3, 505 
535 
558 
8.45 
887 
609 
278 
117 
84 
1.30 
10, .382 
6, 955 
3,427 
185 
263 
9.00 
1,044 
675 
369 
157 
m 
1.45 
10,965 
7,848 
3,117 
583 
893 
9. 15 
1,461 
785 
676 
417 
no 
2.00 
11,290 
8,197 
3, 093 
325 
349 
9.30 
1,923 
907 
1,016 
462 
122 
2. 15 
11,851 
8,509 
3,342 
561 
312 
9.45 
2, 604 
1,0.'J0 
1,554 
681 
143 
2.30 
12, 405 
8,849 
3, 556 
554 
340 
10.00 
3,240 
1,310 
1, 930 
63G 
260 
2.45 
12, 828 
9, 366 
3,462 
423 
517 
