INSECTS AFFECTINC. PARK AND WOODLAND TREES 625 



Lobed oak gall. Cviu'ps s/robilaiui Ostcn Sackcn. A larsj^c, oval l)0(ly 

 consisting of a number of wedge-shapetl parts closely packed together with 

 their pointed extremities attached to the twig, occurs on swamp white oak 

 I pi. 48, fig. 3 1. I'^ach of these wedgelike structures is hard,' corky, and 

 contains a lar\a in the central cell. It is not coninion. 



Large oak apple. Amphiholips couJIhchIhs llarr. This is one of our 

 common oak g.ills. It is nearly globular in shajje, greenish or brown in 

 color dependent on its age, antl its interior is filled with a si)ongy niass in 

 the center of which is a single larval cell. This species is occasionally 

 quite abundant on trees, as may be seen by reference to plate 50. figure i, 

 though it cannot be considered injurious. Mr. Heut(>nmuller slates that a 

 certain number of these galls produce both males and females in June and 

 others females in October or the follow-ing sjiring. These latter are merely 

 a <linic)r|)hic form. 



Larger empty oak apple. Aiiip/iibo/ips iiuniis Ostctn .Sacken. A 

 globular gall closely resembling the oak or May ai)|)le, A. c o n f 1 u e n t u s 

 Harr., occurs on the leaves of scarlet and red oak. It is much like the 

 preceding in general appearance, though considerably smaller and maj- be at 

 once recognized by the nearly empty interior, the small lar\al cell being 

 held in position by numerous radiating filaments. 



Black scrub oak gall. Aniphibolips ilicifoliac Bass. Klongate, fusiform 

 galls tapering at both ends, with the apex more slender and frequently 

 slightly curved, occurs on the leaves and petioles of tlwarf and scrui) oak. 

 It 7s alxnit xYi inches long, half that in diameter, and contains an elongated 

 kernel held in position by radiating fibers. It is green and soft in summer, 

 turning brown and becoming brittle on the approach of winter |])1. 50, 



fig. 2 |. 



Oak leaf apple. Andriciis siiignlaris Wa'^^. A globular, smooth, green 

 gall from Y^^ to ^ inch in diameter, occurs rather commonly on the leaves 

 of red oak. This gall is first green and succulent, turning brown and 

 becoming brittle later in the season. It contains a central oblong ce^U held 

 in place l)y radiating fibers. 



Oak wool gall. Aniiricus lana iMtch. The white or bvilt-col(>red 

 woolly masses composing this gall, occur on the underside of the i)rincii)al 

 veins'of white oak leaves. Within it is composed of numerous small larval 

 cells closely crowded together and attached by their lower ends to the vein 

 of the leaf. It is recorded by BeutenmuUer as common in iIk- vicinity of 

 New York. 



Oak leafstalk gall. yiudriats pctiolicola Bass. These irregularly 

 rounded or fusiform, hard, woody enlargements at the base of the leaf con- 

 tain many cells. The full grown galls are about 5/^ inch in diameter, 

 green in summer, brown in winter and common on several oaks. 



