ILLUSTRATIONS 



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) 12 



2. The California grape root- worm (Adoxus ohscurus): Adult or beetle 15 



3. The grapevine Fidia (Fidia longipes) : Adult or beetle 16 



7 



