MCAL 



TORREYA 



Vol. 26 No. 1 



January-February, 1926 



AN UNUSUAL INSECT GALL ON SCARLET OAK 

 (QUERCUS COCCINEA MUENCH.) 



Arthur Harmount Graves 



Most of US are familiar with such common insect galls on the 

 oak as the beautiful Wool Sower,* often occurring on twigs of 

 white oak — a spherical, woolly mass, which when young, is of an 

 exquisite, creamy-white tint, interspersed with blotches of bright, 

 pinkish-red; the Large Oak Apple — usually about the size of a 

 golf ball, smooth and firm on the outside, but a spongy mass 

 within, and a single thick-walled larval cell in the center; the 

 Oak Bullet Galls, in clusters of two or three or more on the 

 terminal twigs of the members of the white oak group;. as well 

 as many other commonly recurring forms which we know by 

 sight if not by name. 



Last summer, at Hamden, Conn., during the first week in 

 August, I noticed on the callus surrounding an old fire scar on 

 a trunk of a Scarlet Oak peculiar growths in such an unusual 

 location on the tree and of such peculiar shape and bright green 

 color that they were not at first recognized even as galls. In 

 color the growths were a bright green, very close to rivage 

 greenf; in form, almost symmetrically cone-shaped, except that 

 the pointed apex canted slightly to one side; and in size about 

 7 mm. high by 5 mm. in diameter at the base. At first sight they 

 appeared to be some abnormal development of the tree itself — 

 possibly of the nature of adventitious buds. 



Dr. E. P. Felt, to whom the specimens were submitted, stated 

 that they were galls caused by Andricus ventricosus Bass., though 

 slightly abnormal on account of infestation by parasites. Their 



* Felt, Ephraim Porter. Insects affecting park and woodland trees. Vol. 2, 

 pp. 615 flF., Memoir 8, N. Y. State Museum, 1906. See also, by the same author, 

 Key to American Insect Galls. Bull. 200, N. Y. State Museum, 191 8. 



t Ridgway, Robert. Color standards and color nomenclature. Washington, 

 D. C, 1912. See pi. XVIII. 



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