FEEDIXG HABITS OF THE JAPANESE BEETLE. 
9 
Data were collected relative to the rate at which beetles feed on 
apple. These are summarized in Table 3. It was found that under 
clear and warm weather conditions 20 male beetles feeding for an 
average time of 15.6 minutes each consumed 10.448 square milli- 
meters of foliage. This was at the rate of 40.18 square millimeters 
an hour for each beetle. The females feeding on an average 25.05 
minutes consumed 18.133 square millimeters of foliage, which 
amounted to 43.52 square millimeters an hour for eaeh individual. 
It was noticeable that the females made a larger number of feeding 
holes in the leaves than the males and the holes made by the former 
averaged 2.01 square millimeters in area while those made by the 
males were on an average 2.6 square millimeters in area. 
Table 3. — Area eaten by beetles of Popillia japonica during clear weather while feeding 
on Yellow Transparent apple, July, 1921, Riverton, N. J. 
Males. 
Females. 
Beetle No. 
Time spent 
feeding. 
Holes 
made. 
Area 
eaten. 
Time spent 
feeding. 
Holes 
made. 
Area 
eaten. 
1 
Minutes. 
5.75 
3.50 
10.00 
18.75 
3.00 
24.00 
22.50 
28.50 
34.00 
9.00 
18.25 
22.00 
26.25 
5.00 
8.00 
9. .50 
11.00 
12.00 
21. 25 
20.00 
Number. 
1 
3 
J 
5 
8 
I 
2 
7 
7 
1 
1 
1 
3 
1 
9 
6 
Square 
millimeters. 
3.002 
1.079 
6.297 
9.812 
1.216 
13. 166 
14.224 
19.340 
17.622 
5.321 
12. 165 
17. 242 
20. 721 
3.015 
7.270 
7.639 
8.352 
11.334 
14.622 
15. 522 
Minutes. 
15.00 
17.00 
Number. 
5 
5 
Square 
millimeters. 
16. 057 
2 
14. 295 
3 
9.50 
2 
7.679 
4 
18.00 J 4 
11.50 5 
10. 672 
5 
5.347 
6 
25.00 
9 
13. 568 
7 
66.75 
37.00 
18.00 
33.75 
26.00 
29.25 
14 
13 
11 
14 
10 
10 
52. 372 
8 
28. 671 
9 
12. 778 
10 
11.639 
11 
13. 928 
12.. 
20. 954 
13 
21.00 1 12 
17.2.5 11 
16.00 6 
7.00 j 1 
2.00 ! 1 
45.50 i 17 
47.50 15 
38.00 I 15 
11.785 
14 
12. 727 
15 
16 
&:::::::::::::::::::::::::::: 
19 
20 
14. 736 
7.110 
3.327 
41.635 
38.868 
24.511 
Total 
312. 25 
15.61 
85 
4.25 
208. 961 
10.448 
501.00 
180 
362. 659 
Average 
25.05 
9 
18. 133 
Rate per hour 
{ 
40.18 square 
0.062 square 
millimeters 
men. 
Rate per 143.519 square 
hour. . . / 0.067 square 
millimeters, 
inch. 
Experiments to determine the rate of feeding of the beetles were 
also conducted in the insectary. On smartweed, under conditions 
favorable for the activity of the insects, it was found that the males 
fed at the rate of 29.99 square millimeters each hour while in the 
same length of time the females consumed on an average 40.56 square 
millimeters of foliage. On sour cherry foliage during the midday 
hours the rate of feeding was 10.8 square millimeters an hour by the 
males and 9.48 square millimeters by the females. 
The data thus far collected indicate that the females feed some- 
what longer on a plant before leaving than the males. The 
amount of foliage consumed by females in a given length of time is 
slightly greater than by the males. The rate of food" consumption 
and the time spent by the insects in feeding on their various food 
plants during the day are undoubtedly greatly influenced and prob- 
ably largely controlled by the weather conditions prevailing at the 
