142 THE APPLE LEAF HOPPER 



inclosed in a gall-like growth on the under side of the leaf. This louse, 

 which is a wingless female, shortly after dies, leaving the gall filled 

 with her eggs. In about a week or more these eggs hatch, and the 

 3'oung lice migrate, each one forming a new gall. There are several 

 generations, the fall produced young crawling to the roots and hiber- 

 nating in that location. In the spring they attack the root, thus be- 

 coming the "root form."' In the following autumn winged forms are 

 produced on the roots, and crawling up through cracks and crevices 

 in the soil, fly to other vines, laying their eggs thereon and dying. The 

 eggs thus laid are of two sizes, large and small, the larger producing 

 females, the smaller males. After mating the female lays eggs which 

 last through the winter and give rise to another generation in the 

 spring. 



In considering treatment for this pest, it is to be noted that Ameri- 

 can vines are not troubled to the extent that European vines are, be- 

 cause, as one writer claims, there is a thicker and denser bark on 

 the American roots ; yet the Delaware is said to be very susceptible, as 

 are the Isabella and Catawba. The Concord is subject to attack, 

 though rarely to a serious extent. This insect may never be, in Min- 

 nesota, the serious pest it is in the wine-making countries of Europe, 

 where it has been known for a long time. Should it become so it would 

 call for special treatment and energetic work on the part of our fruit 

 growers. 



