INSECTS AFFECTING PARK AND WOODLAND TREES 



643 



five to 10 eggs deposited as previously stated, and thus the life cycle of this 

 extremely interesting form is completed. 



Fig. 176 Hormaphis hamamelidis, sexual generation: <i = young larva; £=male ; 

 female, much enlarged. (After Pergande, U. S. Dep't Agric. Div. Ent. Tech. Ser. 9, 1901) 



Spiny witch-hazel gall 



Hamamelistes spinas us Shimer 



Many spined, green or reddish galls occur on witch-hazel from June to the latter part 

 of October. 



Fig. 177 Hamamelistes spinosus: 

 a— winter egg much magnified ; ^=twig of 

 witch-hazel with young flower buds and 

 eggs in position, natural size (After Per- 

 gande, U. S. Dep't Agric. Div. Ent. Tech. 

 Ser. 9, 1901) 



Fig. 178 Hamamelistes spinosus; rt=mature gall : ^=section of 

 same, natural size (After Pergande, U. S. Dep't Agric. Div. Ent. 

 Tech. Ser. 9, 1901) 



Our knowledge of this insect is due almost entirely to long continued 

 patient investigations by Theodore Pergande of the Bureau of Entomology. 



