26 
THE GRAPE ROOT-WORM. 
of this first feeding. The voracity with which newly emerged bee- 
tles feed is indicated in the poison -spray experiments described on 
page 65. Fifty per cent of newly emerged beetles were killed the 
first day, against 10 per cent of older beetles, both sets being sub- 
jected to identical conditions. 
The feeding of the beetle is confined mainly to the upper surface 
of the leaves; the parenchyma is devoured, leaving characteristic 
chainlike feeding marks, as shown in Plate II. With individual bee- 
tles the length of time of feeding previous to egg deposition varies 
considerably. In Tables II and III is given the record of 16 
individual females, showing a feeding period before oviposition vary- 
ing from 9 to 24 days, with an average of 15.9 days. 
Table II. — Oviposition, feeding , and length of life of individual male and female beetles 
of Fidia viticida in captivity during the summer of 1909 at North East, Pa. 
1. 
2. 3. 
1 
4. 
5. 
6. 
June 30 
June 30 
June 30 
June 30 
July 2 
July 2 
July 8 
July 22 
31 
July 25 
31 
July 26 
40 
July 28 
25 
July 8 
July 21 
17 
July 26 
6 
July 8-9 
July 15 
26 
July 16 
19 
July 27 
14 
July 29 
61 
July 14 
July 21 
15 
July 13 
July 15 
17 
July 28 
14 
Aug. 3 
5 
Aug. 8 
4 
Eggs 
Second oviposition 
July 19 
35 
July 26 
36 
July 29 
31 
July 31 
14 
Aug. 4 
14 
Aug. 7 
23 
Eggs 
Third oviposition 
Eggs 
Fourth oviposition 
Eggs 
Fifth oviposition 
Eggs.... 
Eggs 
Seventh ovinosition 
Eggs 
Fip-hth ovinosition 1 
Eggs 
Ninth oviposition 
Eggs 
Death of male 
Aug. 8 
Aug. 1 
Aug. 26 
Aug. 2 
Aug. 19 
Aug. 3 
July 23 
July 23 
Aug. 25 
Aug. 9 
Death of female 
Aug. 31 
Davs of feeding before oviposition 
Eggs per cluster: 
Minimum 
Average 
Maximum 
Total number of eggs 
Length of life of male 
22.0 
4.0 
25.0 
31.8 
40.0 
127.0 
39.0 
31.0 
21.0 
2.0 
6.0 
11.5 
17.0 
23.0 
57.0 
32.0 
15.0 
4.0 
14.0 
30.0 
61.0 
120.0 
50.0 
33.0 
21.0 
1.0 
15.0 
15.0 
15.0 
15.0 
23.0 
23.0 
13.0 
4.0 
4.0 
10.0 
17.0 
40.0 
54.0 
38.0 
17.0 
6.0 
14.0 
25.5 
36.0 
153.0 
Length of life of female 
60.0 
