90 THE REPORT OF THE No. 19 



C. — Galls on the roots. 



Large, irregularly rounded, reddisii-brown galls from 1 to 2 inclies in 

 length; polythalamous. Rose Root Gall — Rhodites radicum (O.S.)- 

 Rosa sp. 



Affecting Spir^a. 



A pod-like gall formed by the folding of the leaf along the midvein. 

 Spiraea Pod Gall — Cecidomyia salicifolial — Spiraea tomentosa, S. salici- 

 folia and S. betulsefolia. 



A bud-like, sessile gall in the axil of the leaf. Meadow Sweet Bud 

 Gall — (Undescribed) — Spiraea salicif olia . 



Small, cone-shaped galls on either the upper or lower surface of the 

 leaf. Spiraea Cone Gall (Undescribed) — Spiraea salicifolia. 



Affecting Sumac. 



The leaf margin rolled tightly upward and inward on both sides. Sumac 

 Leaf -margin Gall — Eriophyes sp. — Plate K., fig. 3. Rhus typhina. 



Irregular, rounded, dimple gall, convex on the upper or under side of 

 the leaf. Green to red or purple in color; inside clothed with white tri- 

 chomes. Poison Ivy Dimple Gall — Eriophyes sp. — Plate G., fig. 5. Rhus 

 radicans. 



Large, smooth, rounded galls, somewhat resembling a tomato in shape, 

 on the under sides of the leaves. Sumac Potato Gall — Pemphigus rhois. 

 Rhus typhina. 



Affecting Strawberry. 



A much elongated, cylindrical enlargement of the petiole of the leaf, 

 1 to 4 in. long and 1-10 to 1-6 in. in diameter. Its surface, owing to slight 

 annular constrictions has a more or less segmented appearance. The con- 

 strictions are seldom more than about .5 mm. deep and as a rule do not occur 

 at regular intervals. Sometimes they are found every 1-16 of an inch, but in 

 other cases they are as much as an inch apart. The surface of the gall is 

 nearly red, or greenish, and is pubescent like the rest of the petiole. The 

 texture is pulpy. The gall is polythalamous, as few as 10 and as many as 

 35 small chambers having been counted in specimens examined. These are 

 all centrally situated and each contains a single, white larva, August 7, 

 1907. Occasionally two separate galls or gall clusters are found on a single 

 petiole. Strawberry Petiole Gall. Plate R., fig. 7. Fragaria Yirginiana. 



Affecting Touch-me-Not. 



Globular, succulent, semi-transparent, at base of flowers. Touch-me- 

 not Flower Gall — Cecidomyia impatiens (O.S.). Impatiens fulva. 



Green, succulent, globular or irregularly rounded swelling on the 

 stem, petiole or leaf. Touch-me-not Stem and Leaf Gall — CecidoTnyia. 

 — Plate 0., fig. 2. fulva (Bent) — Impatiens fulva. 



Affecting Tulip Tree. 



Hollow swellings, varying from 5 to 2.5 cm. in length on the midrib 

 and lateral veins of the leaves. Tulip Tree Midrib Gall — Cecidomyia tul- 

 ipifera — Liriodendron tulipif era . 



Affecting Yervain. 



An oval, hard and woody gall, an enlargement of the stem. Blue Ver- 

 vain Stem Gall (Undescribed) — Verbena hastata. 



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