362 The Spraying of Plants. 



bodies are produced on the under side of the leaves ; they con- 

 tain the spores which preserve the fungus through the winter. 



Treatment. The plants, and the soil about them, should be 

 sprayed in early spring before growth has commenced with the 

 copper sulphate solution. After the buds have burst the Bor- 

 deaux mixture should be used, or some clear fungicide which 

 will not stain the leaves. These applications should be contin- 

 ued until midsummer at intervals of two or three weeks. Raking 

 and burning the leaves in the fall will also diminish the trouble. 



INSECT ENEMIES. 



Mealy-bug. See under GREENHOUSE PESTS. 



Rose-chafer ; Rose-beetle ; Rose-bug (Macrodactylus subspinosus, 

 Fabr.). Description. The beetles appear, as a rule, early in 

 June. They are about half an inch in length and of a yellowish- 

 brown color, the legs being pale red. The beetles feed for about 

 a month after the time of their first appearance. They devour 

 nearly all kinds of foliage, and in some localities fruit planta- 

 tions are annually almost ruined by these insects. Shortly be- 

 fore the disappearance of the adults, the eggs are laid in the 

 ground near the surface. The grubs feed upon the roots of 

 various plants and in the fall they descend below the frost line 

 and there pass the winter. In the spring they ascend to the 

 surface and pupate, the adult emerging as above stated. There 

 is but one brood each year. 



Treatment. No satisfactory remedies for the destruction of 

 the rose-beetle are known. The insect can persist only on 

 sandy land, for heavier soil prevents the grubs from descending 

 to a proper depth. It is, therefore, only on sandy land that the 

 pest is to be feared. The following methods of exterminating 

 the insect have been recommended, but none are entirely satis- 

 factory : " Hand picking. Knocking off on sheets early in the 

 morning. Bagging. Pyrethrum. Kerosene emulsion. Py- 

 rethro-kerosene emulsion. Eau celeste. It is said to prefer 

 Clinton grapes, spireas, rose-bushes, and magnolias, and it has 

 been suggested that these plants be used as a decoy. Open 

 vials of bisulphide of carbon hung in bushes and vines are 

 recommended by some. Sludge-oil soap, a manufactured ma- 

 terial. Spraying with dilute lime whitewash. Hot water, at 

 a temperature of 125 to 130 F. To prevent the insects from 



