Cherry, Chrysanthemum. 275 



not require such repeated applications, since the fruit matures 

 earlier in the season. It is also more unsafe to use the Bor- 

 deaux mixture, on account of the danger of staining the fruit ; 

 the ammoniacal solution of copper carbonate or some other 

 clear fungicide will be found a better remedy after the cherries 

 are one-half grown. The Bordeaux mixture may be safely ap- 

 plied as soon as the blossoms have fallen and the fruit has set. 



Leaf Blight (Cylindrosporium Padi. Karst.). This disease is 

 fully treated under PLUM, which see. 



Powdery Mildew (Podosphcera Ozycanthce, DeBary). See 

 under APPLE. 



Black Knot (Plowrightia [Spkceria] morbosa, Sacc.). See 

 under PLUM. 



INSECT ENEMIES. 



Canker-worm (Paleacrita vernata, Peck). See under APPLE. 



Plum Curculio (Conotrachelus nenuphar, Herbst). See under 

 PLUM. 



Slug (Selandria Cerasi, Peck). Description. The mature 

 insect is a black fly having four wings. The eggs are laid in 

 small openings made in the leaf by the insect. They hatch in 

 about two weeks. The larvae mature in about four weeks. 

 They bear a certain resemblance to a tadpole, being shiny, 

 dark-green worms, about half an inch long (Fig. 75). They eat 

 the soft tissues of the leaves, only the larger veins remaining. 

 In severe cases the trees may be entirely defoliated. There are 

 two broods each year. 



Treatment. Fortunately this insect may be overcome very 

 easily. Dry-slaked lime dusted over the leaves destroys the 

 pest, and if air-slaked lime be freely used it will answer the 

 same purpose. Pyrethrum, hellebore, or some form of arsenic, 

 applied dry or with water, will also rid the tree of the insect. 

 Dry road-dust has been recommended, but is not always satis- 

 factory. 



CHRYSANTHEMUM. 

 FUNGOUS DISEASES. 



Leaf Spot (Septoria Chrysanthemi, E. & D.). Description. 

 The fungus causing leaf spot of chrysanthemums first causes 



