266 MAINE AGRICULTURAL EXPERIMENT STATION. I914. 



PYRUS AMERICANA, P. SITCHENSIS, etc. Mountain Ash. 

 ScHizoNEURA LANiGERA. Woolly Aphid of Apple. 



This species is as common on Pyrus americana, P. sitchensis 

 and other mountain ashes about Orono as it is on the apple. 

 It migrates in Maine to the mountain ash in June as it does to 

 the apple and the return migration takes place in the fall. For 

 a fuller discussion of this species see Pyrus malus. 



Aphis pond, The Green Apple Aphis, is common on our 

 native mountain ash. This is discussed under apple. 



PYRUS MALUS. Apple. 



The most serious aphids which have been recorded for the 

 apple in Maine are discussed in other publications of the 

 Maine Agricultural Experiment Station so that they need only 

 be touched lightly here. 



ScHizoNEURA LANIGERA {amcricana in part of authors). The 

 Woolly Aphid of the Apple. 



This species causes terminal leaf cluster or rosette on the 

 elm in the spring and migrates to the apple for the summer 

 generations, fall migrants returning to the elm (Ulmus anieri- 

 cana) in the fall where the true sexes are developed and the 

 wmter egg deposited. The life cycle of this species is further 

 complicated by hibernating nymphs which remain about the 

 apple tree through the winter, and by root forms which are 

 found throughout the year on apple roots. How long, under 

 favorable climatic conditions, the apple can serve as a host 

 for this pest independent of reinfestation from the elm has 

 not been ascertained. In Maine an annual spring and fall 

 migration occurs. 



This species can be distinguished from others of the same 

 genus inhabiting the leaves of elm by the antenna and the 

 character of the wax glands. 



Aphis avenae Fab. The Aphis of Oat and Apple. 



(Figure 90, G-I. Figure 96, D.) 

 This species migrates from the apple and certain other mem- 

 bers of the rose family to the oat or other grasses for the 



