101 



8. Pear-hJight, Appk-hlio-hU Fire-blight, Twig-hlight (p. 124). 

 A contag-ious disease of the pear, apple, and quince, caused by 



bacteria multiplying- within the living- substance of the tree. Young- 

 g-rowth dies rapidly, beginning- at the tips of the twig-s, the leaves 

 aad bark soon becoming- first reddish and then almost inky black 

 and drying- up. Continues dormant in the diseased tissues throug-h 

 the winter, and may revive and spread in spring. 



9. Blach-kuot (p. 125). 



A contag-ious fungous disease of the plum and the cherry, pro- 

 ducing- rough, hard, sooty-black warts or knots on the twigs or 

 branches, often extending for several inches along one side. 



10. Peach Fniit-spoi (p. 127). 



A fruit disease of the peach, apricot, cherry, and plum due to 

 the fungus Cladosporiiim carpophilum. Affects also the twigs of 

 nursery stock, producing there purple blotches on the bark which 

 may crack open when the attack is severe. Conveyed from tree to 

 tree and from twig to fruit. Also attacks the leaves, producing 

 small holes. On the fruit makes dull brown or black spots, which 

 may run together, sometimes covering the surface of the peach. 

 The diseased skin often cracks, admitting spores of the rot fungus. 



11. A)ith}-ac)iosc of Raspberry (^-g 126). 



A fungous disease of the raspberry and blackberry, producing 

 small purple spots on the bark, which become gray with a purple 

 rim as they expand. Spreads to leaf-stem and leaves. Dormant 

 on old canes in winter. 



Injurious to the Leaf or Bud. 



12. Plant-lice, or Aphides (pp. 127-129). 



Small sluggish insects, clustered in great numbers on the under 

 surface of leaves. Most abundant on the younger growth. The 

 greater part wingless, but most kinds with a varying percentage of 

 winged individuals intermingled. Often much visited by ants. 

 Many species, infesting nearly all kinds of plants. Cause curling 

 of leaves and dwarfing of the season's growth. Usually pass the 

 winter in the egg on buds and twigs, hatching in early spring. 



13. The Apple Leaf-criimpler (p. 129). 



Found in winter as a half-grown caterpillar in clusters of dead 

 leaves webbed together and fastened to twigs of apple-trees. 

 Protected by a slender, crooked, leathery tube within this leaf 

 cluster. Comes out in spring and feeds upon the leaves, the buds, 

 and even the bark of the youngest growth. Commonest on the 

 apple, but found also on the plum, cherry, peach, and quince. 



