100 



2. The Black Peach- Aphis^ (p. 107). 



A short, broad, shining- brownish-black aphis, infesting- the 

 roots of the peach and plum, and appearing- also on the twigs, buds, 

 and leaves. Winters as a developed insect on the roots. 



3. Tlic Crown-gall (p. 110). 



A conspicuous wrinkled or roughened knot with a wart-like 

 surface, g-rowing most commonly from the crown of the tree or its 

 vicinity. Especially likely to staxt from a grafting scar or other 

 place of injury. Sometimes also borne by the larg-er roots or 

 appearing on the trunk above ground. Affects nearly all deciduous 

 fruits, including- the apple, peach, apricot, pear, raspberry, black- 

 berry, cherry, plum, g-rape, and quince. Believed to be contagious, 

 and is often fatal, especially to young trees. Not certainly the 

 same disease, however, on all of these kinds of fruits. 



4. 71ic Root-rot (p. 111). 



A destructive, contagious, and incurable disease of the roots of 

 trees, due to certain toadstool fungi, and resulting- in the death and 

 decay of the roots and the g-radual destruction of the tree. Strings 

 and sheets of white fung-ous growth between the bark and wood of 

 the dead root, and black threads or cords of fungus mycelium run- 

 ning- over the surface of the roots and through the dirt. Toadstools 

 spring from the base of the trunk of badly affected trees, and masses 

 of gum also exude about the crown. Commonest on old woodlands. 



Injurious to the Bark or Wood. 



5. The Woolly Aphis (p. 106). 



(See above under No. 1). 



6. Scale Insects or Bark-lice (p. 112). 



Minute inactive insects, in most species concealed beneath thin, 

 nearly structureless scales which adhere to the surface of bark or 

 leaf. Colors varying, according to kind, from snow-white to g-ray 

 or dark brown or even sooty black, and form likewise varying from 

 circular to oval or linear. Some species wintering as eggs under 

 the dry scale, and others as developed but dormant insects partly 

 or fully grown. Various species infest practically all varieties of 

 trees and shrubs. 



7. The Peach-tree Borer (^■^. 121). 



A yellowish white, grub-like caterpillar, about an inch long, 

 with dark head and neck and eight pairs of legs. Mines the bark 

 and sap-wood of the peach, plum, apricot, and cherry, commonly 

 within a foot or so of the ground, causing profuse exudations of 

 gum. Winters beneath the bark under ground or within the ex- 

 uded gummy mass. 



