INSECTS AFFECTING PARK AND WOODLAND TREES 



64I 



branches of twigs, generally near the base of buds or leaf scars. The eggs 

 resemble those of the common apple plant louse. Aphis m a 1 i Fabr., 

 though they are considerably smaller. The young stem mother is but 

 slightly larger than the egg and appears in the latitude of "Washington 

 about the middle of April. She is a dull black color covered with a 



Fig. 174 H o r m a p h i s h a m a m e 1 i d i s, 3d generation, fourth or final stage: 

 «j=dorsal view ; ^^ventral view; r^lateral view , */=dorsal view, showing tiie 

 arrangement of pores ; f=end of body. ( After Pergaiule, U. S. Dep't Agric. Div. 

 Ent. Tech. Ser. 9, 1901) 



delicate, slightly bluish secretion and ornamented with a waxy secretion as 

 shown in figure 172. She molts three times, attaining maturity the middle 

 of May and from then producing 4-6 young till about the middle of June. 

 The second or winged generation, the young of the stem mother, com- 



