30 
THE GRAPE ROOT-WORM. 
NUMBER OF EGGS DEPOSITED BY INDIVIDUAL FEMALE BEETLES. 
The total number of eggs laid per female seems to depend upon the 
vitality of the individual insect, and undoubtedly also upon the 
amount of feeding by the adult. In the experiments of Table II 
the average was 112 eggs per female, with a maximum of 263 and a 
minimum of 14 eggs. In Table V is presented the results of the so- 
called ''stock-jar" experiments, in which several beetles were 
confined. 
Table V. — Egg deposition of the grape root-worm by about 57 female beetles in eight 
stock jars, as observed in 1909 at North East, Pa.; with a summary of the length of 
life of the beetles for each stock jar. 
Stock jars. 
II. III. 
IV. 
VI. VII. 
VIII. 
Number of 
beetles. 
25. 
12. 
Date of the 
emergence. 
July 
July 10. 
July 11. 
July 12. 
July 13. 
July 16. July 19. 
July 22. 
Date of ovi- 
position: 
July 19.. 
July 20. . 
July 21.. 
July 22.. 
July 23.. 
July 25.. 
July 26.. 
July 28.. 
July 29.. 
July 30.. 
July 31 . . 
Aug. 1... 
Aug. 3... 
Aug. 4... 
Aug. 5... 
Aug. 6... 
Aug. 7... 
Aug. 8... 
Aug. 9... 
Aug. 11.. 
Aug. 13.. 
Aug. 14.. 
Aug. 19.. 
Aug. 23.. 
Aug. 27.. 
Total ovi- 
position 
Eggs per 
female. . 
107 
70 
64 
96 
94 
43 
81 
22 
121 
76.5 
in;, 
33 
44 
21 
328 
31.2 
29 
138 
55.2 
37.1 
443 
55.3 
150 
25.0 
472 
134.9 
246 
82.0 
LENGTH OF LIFE OF BEETLES. 
Maximum 
number of 
days 
50 
48 
23 
47 
53 
13 
46 
53 
Average num- 
ber of days.. 
21.6 
20.3 
12.0 
15.9 
23.5 
5.0 
28.7 
20.2 
Minimum 
number of 
days 
0 
5 
4 
3 
2 
3 
6 
1 
