88 THE REPORT OF THE No. 19 



Large, irregular galls on tlie tips of the twigs, consisting of a double 

 row of lamina ; between these two layers are large numbers of aphids. Vaga- 

 bond Gall — Peinphigus vagahundus — Populus deltoides. 



Irregular, spherical gall developed at the junction of the petiole and 

 blade of leaf. Poplar Petiole Gall — Pemphigus populicaulis — Plate I. fig. 

 3. Populus deltoides. 



Circular, flat or slightly convex, frost-like patches varying from 2-3 

 mm. in diameter; on the upper side of the leaf. Large-toothed Aspen Frost 

 Gall — Eriophyes sp. — Populus grandidentata. 



Circular depressions dimple always on the lower side of the leaf. On 

 the upper side it appears as a green red circular elevation. Large-toothed 

 Aspen Convex Gall — Eriophyes sp. — Plate M. fig. 1 & 2. Populus grandi- 

 dentata. 



Dimple-like galls on the upper side of the leaf of the Aspen, Aspen 

 Dimple Gall — Erhphyses sp. — Plate M. fig. 3. Populus tremuloides. 



Irregular, warty protuberances on the midrib or other veins of the leaf 

 and extending beyond both surfaces but chiefly the upper one. Large- 

 toothed Aspen Vein Gall. Populus grandidentata. 



Irregular tubercular masses of closely-packed small reddish-green pro- 

 tuberances on the stem. Unsightly Poplar Gall — Eriophyes sp. Populus 

 tremuloides. 



A depression on the lower surface of the leaf, 4-12 mm. in diameter and 

 2-5 mm. in depth. Under surface of gall is orange yellow — Eriophyes sp. 

 — Plate D., fig. 3. Populus italica. 



Margin of leaf distorted and curled. Eriophyes sp. — Plate T., fig. 1. 

 Populus tremuloides. 



B. — Galls on the stem. 



Irregular swellings caused by a species of Woolly Aphis, on the smaller 

 branches and twigs of the Cottonwood. Woolly Aphid Stem Gall — 

 Schizoneura sp. Populus deltoides. 



Irregularly oval, about 1-3 to ^ inch long, smooth and about the same 

 color as the bark. Usually on one side of a branch but sometimes nearly 

 encircling it. Aspen Egg Gall — Agronyzaaoneiventris (Fallen). — Plate 

 A., fig. 8. Populus tremuloides. 



Affecting Genus Prunus. 



Reddish, slender pouch-galls, somewhat irregular and pubescent, 3-4 

 mm. long and .5-1 mm. in diameter. Pin Cherry Pouch Gall — Eriophyes 

 sp. Prunus pennsylvanica. 



Green or rosy-red pouch gal on the upper side of the leaf, .5-6 cm. in 

 length. The gall is constricted about half way to the leaf. Black Cherry 

 Pouch Gall — Eriophyes sp. Prunus serrotina. 



Green or reddish pouch gall on the upper side of the leaf, differing from 

 the Black Cherry Pouch Gall in that the aperture is not funnel-shaped. 

 Choke Cherry Pouch Gall — Eriophyes sp. — Plate G., fig. 2. Prunus vir- 

 giniana. 



A very long, slender pouch-gall, green or whitish on either side of the 

 leaf. Wild Plum Pouch Gall — Eriophyes sp. — Plate K., fig. 2. Prunus 

 americana. 



A tubercular growth, encircling base of buds and shoots. Plum Bud 

 Gall — Eriophyes phloeocoptes . Prunus domestica. 



A club-shaped, monothalamous gall with one or two leaves growing 

 from its side. The gall is an enlargement of the terminal buds of young 



