[L LUSTRATIONS. 
PLATES. 
Page. 
Plate I. The grape root- worm (Fidia viticida). Fig. 1. — Female beetle oviposit- 
ing. Fig. 2. — Beetle on the lower side of a grape leaf. Fig. 3. — 
Egg-cluster with average number of eggs. Fig. 4. — Grape cane, 
showing eggs beneath the bark. Figs. 5, 6. — Full-grown larvae. 
Fig. 7. — Pupa in cell. Figs. 8, 9. — Lower and upper views of pupa. 
Fig. 10. — Openings in the ground from which beetles emerged. 
Frontispiece. 
II. Feeding marks on grape leaves, made by the beetle of the grape root- 
worm. Fig. 1. — Appearance of fresh feeding marks. Fig. 2.— 
Feeding marks which have become enlarged with the growth of the 
leaf 14 
III. Feeding marks on the larger roots and underground part of the stem 
of a grapevine by larvae of the grape root-worm, resulting in the 
death of the plant 14 
IV. Destruction of root fibers by larvae. Fig. 1. — Five-year-old grapevine 
with normally developed root-system; enlarged portion showing 
root fibers. Fig. 2. — Four-year-old grapevine, showing result of 
feeding by larvae of the grape root- worm 16 
V. Ridge of soil under trellis. Fig. 1. — Vineyard view in the spring, 
showing ridge of undisturbed soil under the trellis. Fig. 2. — Vine- 
yard view, showing ridge of soil under trellis as formed at the last 
cultivation of the preceding summer. North East, Pa 62 
VI. General view of Mr. Roscoe Davidson's vineyard at North East, Pa., 
where spraying experiments against the grape root- worm were con- 
ducted during 1907, 1908, and 1909 70 
VII. Views of experimental plats in Mr. Roscoe Davidson's vineyard at 
North East, Pa. Fig. 1. — Retarded growth of vines in the un- 
sprayed plat. Fig. 2. — Vigorous growth of vines in the sprayed 
plat 74 
VIII. Views of the Porter experimental vineyard, showing comparative 
growth of the vines in 1907 at the beginning of the experiment 
(upper figure), and in 1909 at the end of the experiment (lower 
figure). North East, Pa 80 
IX. Condition of fruit on vines in plats of the Porter experimental 
vineyard. Fig. 1. — Average condition of berries in the untreated 
plat. Fig. 2.— Average condition of berries in the treated plats. 
North East, Pa., 1909 80 
X. Spraying outfits for vineyards, in use at North East, Pa. Fig. 1. — 
Spray-mixing plant. Fig. 2. — Gasoline-engine sprayer in opera- 
tion. Fig. 3. — Compressed-air sprayer. Figs. 4, 5. — Horsepower 
or geared sprayers 86 
TEXT FIGURES. 
Fig. 1. Map showing distribution of the grape root- worm (Fidia viticida) I'J 
2. The California grape root-worm (Adorns obscuriis): Adult or beetle. . . . L6 
3. The grapevine Fidia (Fidia lonyipcs): Adult or beetle 16 
7 
