526 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



?iatural Enemies 



An undetermined Internal parasite has 

 t)een bred from this species. 



E. O. EssiG 



Green Apple Aphis 



Aphis ponii or Aphis mali 



These lice lay their shiny black eggs 

 in October and November in crevices 

 of the bark and in scales of the buds 

 of the apple trees. After the first brood 

 hatches in the spring about the time of 

 the unfolding of the first buds and until 

 late in the autumn they may be found 

 at all times on the apple trees. Their 

 presence in the spring may be detected 

 by the curling of the tender leaves on 

 the under side of which the aphids make 

 their home. 



These lice, like others of the family. 

 eat more than they can assimilate and 

 the excess exudes from the "honey tubes" 

 near the posterior end or from the anal 

 opening. "This liquid is highly jirized 



by the ants, which are nearly always 

 to be found running over and around 

 the aphis colonies. It is a great mistake 

 to suppose that ants eat the aphis or 

 Injure them in any way; on the other 

 hand ants often protect and aid some 

 species of lice in return for the sweet 

 liquid, called honey dew, of which they 

 are so fond. 



*"The honey dew is directly respon- 

 sible for the black, sooty fungus growth 

 which nearly always follows the appear- 

 ance of the green leaf aphis. The fun- 

 gus thrives on this honey dew, and soon 

 clogs the breathing pores of the leaves, 

 resulting in their turning brown, wither- 

 ing and dying. In this manner it may 

 prove quite injurious to leaves not actu- 

 ally infested by aphids because such quan- 

 tities of honey dew drops from aphis 

 colonies to the leaves beneath." 



The first two or three generations of 



• R. I. Smith. North Carolina Experiment 

 Station. Bulletin 206. 



Fig. 2. Apple Aphis. A, stem mother just hatched from egg: B, winged female such as 

 migrate from tree to tree during summer ; C. wingless female of summer form : D, leaves 

 curled by this aphis : E. eggs magnified : F. buds just opening, showing newly hatched 

 eggs; G.twig showing eggs as they appear in the winter time. (Montana Experiment Sta- 

 tion) 



