THE GRAPE PHYLLOXERA IN CALIFORNIA. 
87 
location of the sexed eggs. Taking the sum of these discussions, 
it appears that they are placed on the underside of the leaves and 
more abundantly in the bark, generally between the year-old layer 
and that of the current year, and are fastened to the inner side of 
the former. Occasionally eggs are found at the base of canes where 
the new wood joins the old, and rarely on the vine supports (stakes). 
They are laid on both viniferae and resistant vines, but preferably on 
the latter. 
Observations were conducted in small cages, and in a few instances 
on living vines in pots. In the latter instances eggs were found laid 
on both the foliage and bark. Many different kinds of cages were 
used and experiments with different degrees of light, moisture, and 
temperature were conducted. Vine leaves and pieces of bark were 
inclosed in the cages. As a rule, the migrants, though primarily 
attracted to light, deposited their eggs in semidarkness. They laid 
them on the leaves and more rarely on pieces of bark offered, but 
often also on the sides, lid, and floor of the cages and in cracks. In 
1911 the observations tabulated in Table XXVII occurred. 
Table XXVII. — Sexual production of the grape phylloxera, Walnut Creek, 
Calif., 1911. 
Number 
of mi- 
grants. 
:m 
45 
103 
Date and location of migrants. 
Aug. 4-6: Riparia vine in pot. . . 
Aug. 7-8: Vinifera vine in pot . . 
Aug. 10-12: Riparia vine in pot. 
Aug. 13, 14: Vinifera vine in pot. 
Aug. 15: Riparia vine in pot 
Aug. 16: Riparia vine in pot 
Aug. 17 : Glass tube in drawer 
Aug. 18, 19: Riparia leaves in petri dish 
Aug. 19: Leaves in petri dish 
Aug. 23: Leaves in petri dish 
Aug. 24: Riparia leaves in laboratory. 
Aug. 25, 26: Riparia leaves in petri dish. 
Aug. 25, 28, 29: Riparia leaves in petri dish. 
Sept. 2-17: Vinifera vine in pot 
Sept. 19-23: Riparia vine in pot. 
Sept. 2.5-29: Riparia vine in pot. 
Number 
of sexual 
eggs de- 
posited. 1 
Date of 
deposi- 
tion. 
Aug. 
Aug. 16 
Aug. 15 
Aug. 20 
...do 
...do 
Aug. 21 
Aug. 22 
Aug. 23 
Aug. 19 
Aug. 23 
Aug. 25 
Aug. 26 
Aug. 27 
Aug. 28 
Aug. 29 
Aug. 27 
Aug. 28 
Aug. 30 
Sept. 3 
Sept. 25 
Sept. 29 
Date of 
maturing 
of sexes. 
Aug. 26 
Aug. 28 
Aug. 30 
Sept. 6 
Aug. 30 
Sept. 2 
Oct. 4 
Oct. 5 
Oct. 6 
Number 
of sexes 
ma- 
tured. 2 
1 Thirteen female and three male eggs. 
2 All maturing sexuals were females. 
Table XXVIII.— Summary of Table XXVII. 
Number of migrants 734 
Number of sexual eggs deposited 171 
Number of sexual eggs hatched 13 
