8 
BULLETIN" 1154, U. S. DEPARTMENT OF AGRICULTURE. 
period between July 18 and 23, 1921, 25 males and 25 females were 
timed and the length of the feeding periods noted between the hours 
of 7.30 and 10 a. m. on apple foliage. Similar observations were 
made between the hours of 11 a. m. and 2 p. m. Table 2 gives the 
data thus obtained. From these data it was found that under condi- 
tions favorable for movement and activity among the beetles the 
average length of time which the male beetle fed was 21.65 minutes 
between the hours of 7.30 and 10 a. m. During the same period the 
females fed for an average period of 40.24 minutes. In the second 
series of observations, between 11 a. m. and 2 p. m., the males fed for 
an average period of 23.3 minutes and the females 46 minutes before 
flying to other food plants. 
Table 2. — Length of time beetles of Popillia japonica spent feeding on apple foliage 
between 7.30 and 10 a. m., and between 11 a. m. and 2 p. m., July, 1921, River- 
ton, N. J. 
Time spent feeding. 
Beetle No. 
Males. 
Females. 
7.30 to 
10 a.m. 
11 a.m. to 
2p.m. 
7.30 to 
10 a. m. 
11 a. m. to 
2 p.m. 
1 
Minutes. 
12.50 
22. 55 
16.50 
14.00 
33.50 
2.75 
41.50 
28. 50 
28.00 
32.00 
19. 25 
52.25 
11.25 
6.00 
2.75 
27.00 
18.50 
23.50 
28.00 
34.25 
38.00 
18.25 
10.00 
14.75 
6.00 
Minutes. 
7.00 
4. 50 
26.25 
3.00 
2.50 
18.00 
7.75 
34.50 
16.25 
11.25 
39.25 
21.00 
5.50 
14.75 
13.25 
49.50 
27.50 
101. 75 
22.00 
Minutes. 
27.50 
22.00 
38.25 
49.75 
81.00 
33.50 
42.75 
26. 25 
76.50 
43.50 
32.25 
29.00 
86.25 
54.00 
40.00 
14.25 
71.50 
70.50 
19.00 
Minutes. 
64.50 
2 
47.25 
3 
21.75 
4 
7.75 
5 
72.00 
6 
120.00 
7 
18.50 
8 !.. 
48.25 
9 
39.50 
10 
67.50 
11 
34.25 
12 
22.75 
13 
14.75 
14 
43.50 
15 
52.25 
16 
31.25 
17 
29.50 
18 
88.25 
19 
63.25 
20 
63.25 1 27.75 
42.00 : 10.00 
11.50 i 36.75 
20.50 | 26.00 
3.00 8.25 
16.50 39.25 
99.00 
21 
21.50 
22 
36.50 
23 
42.00 
24 
34.25 
25 
30.00 
Total 
541.25 i 582.25 
21.65 
1,005.75 
40.24 
1,150.00 
46.00 
Observations were also made relative to the length of the feeding 
period of the beetles on grapes between the hours of 12.15 and 4 p. m. 
The data were collected from 25 beetles of each sex. They indicate 
that on grapes the average length of time the males spent in feeding 
was 21.54 minutes, while the females fed for an average time of 
40.18 minutes. On July 29 the weather was cloudy, with a misty- 
rain falling all day, and observations were made relative to the length 
of the feeding period on the foliage of sour cherries. Under these 
conditions the majority of the beetles were not feeding, although 
they remained on the foliage throughout the period of observation. 
The feeding was so erratic and of such small amount that no attempt 
was made to determine the actual time spent by the beetles in this way. 
