28 
THE GRAPE ROOT-WORM. 
Table III. — Summary of oviposition experiments, recorded in Table II, showing the final 
average, maximum, and minimum, of egg deposition by individual female beetles in 
captivity, at North East, Pa., 1909. 
Observations. 
Average. 
Maximum. 
Minimum. 
Number of days previous to first oviposition 
15.9 
24 
9 
Number of times of oviposition 
4.4 
9 
1 
Number of davs between ovipositions 
3.6 
15 
1 
Number of eggs per cluster 
24.0 
61 
4 
Number of eggs per female 
112.0 
263 
14 
In Table V (p. 30), giving records of experiments with a large 
number of beetles in stock jars, where only the minimum length of 
time could be verified, this feeding period is shown to have covered 
from 9 to 10 days. Feeding is continued for almost the entire length 
of life of the beetle, and it has undoubtedly a direct bearing upon the 
number of eggs deposited. 
MATING AND ITS BEARING UPON EGG DEPOSITION. 
Mating of beetles has been observed a few days after their emer- 
gence. It has been found to take place several times before the first 
egg deposition, the day previous to oviposition, and also after each 
oviposition. Repeated mating, however, is not essential in bringing 
about further egg depositions, as shown in one instance under obser- 
vation (Table II, jar No. 13). In this jar the male and the female 
beetles were confined together shortly after emerging. Mating took 
place July 27, 28, and 30. The male beetle escaped August 5, yet 
oviposition by the same female occurred on August 7, 11, 14, 19, and 
23 without further mating. 
PROCESS OP EGG DEPOSITION. 
As the time of egg deposition approaches, the female beetles cease 
feeding for a day or two and become sluggish and somewhat inactive. 
They generally seek the shady places and are at this period to be 
found on the canes of the vines, where they are less easily detected. 
The eggs are deposited almost entirely under the loose bark on the 
canes and trunk; very rarely, however, they are placed on other parts 
of the vine. The female inserts the eggs beneath the loose bark by 
means of the protrusible ovipositor (fig. 11, e) and places them side 
by side in a cluster of a single layer. An adhesive substance, secreted 
by the female, glues the eggs together, and the entire mass is fastened 
either to the cane or to the inner surface of the loose bark (PI. I, figs. 
3, 4). Individual female beetles have been observed to move along 
the canes in search of suitable places for egg deposition. In this 
process the hind end of the body touches the cane, and as the insect 
slowly passes along the ovipositor is inserted into the cracks or crev- 
ices, apparently testing the fitness of these places for egg deposition. 
A female beetle is shown in Plate I, figure 1, photographed in the act 
of oviposition. 
