INSECTS AFFF.CTING PARK AND WOODLAND TREES 



643 



five to lo e^'i^s clrijositcd as prmiousl) sUitcc!, and thus tlu- life cycle of this 

 extremely intert;stii\i;- form is completed. 



Fig. 176 Hormaphis h a m 3 nn- I i d i s , sexual generation: «— young larva; i— male ; 

 c— female, much enlarged. (After rerg.aiide, U. S. Dep'l Agric. Div. Ent. Tech. Ser. 9, 190O 



Spiny witch-hazel gall 



Haiuamcl/stcs spinosiis Shimer 

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



of Oct. liter. 



Fig. 177 Hamamelistcs 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 s p i n o s u s ; 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. 



