APHIDS INJURIOUS TO ORCHARD FRUITS. 



23 



less and winged forms are shining deep brown to black, while the 

 color of the young ranges from amber through various shades of 

 brown. The young stem-mothers are deep greenish. 



On account of their early hatching in spring the young stem- 

 mothers do not find leaf food available. They therefore attack 



Fig. 16. — The mealy plum aphis {Ilyalopterus arundinis) : Infested plum 

 foliage. (Original.) 



the buds even before these show any signs of bursting. Sometimes 

 the stem-mothers will feed in this manner for nearly a week before 

 the buds begin to open. As soon as the leaves are formed the young 

 insects attack them and cause them to curl. As they spread from 

 leaf to leaf a large and conspicuous cluster of curled-up leaves 

 (fig 17) is formed, within which the insects feed. 



