284 The Spraying of Plants. 



year. The beetles feed upon the plants mentioned above, and 

 also upon other garden vegetables. 



Treatment. See under STRIPED CUCUMBER-BEETLE. 



Striped Cucumber-beetle (Diabrotica vittata, Fabr.). Descrip- 

 tion. The beetle appears early in spring and attacks the leaves 

 and stems of the cucumber and related plants. Eggs are laid, 

 these being placed in the soil at the base of the plants. The eggs 

 soon hatch and produce small whitish worms that are about half 

 an inch long when full grown. They feed upon the roots of 

 the plants, causing the latter to wilt and die. The larvse mature 

 in about two months, the insect passing the winter in the beetle 

 form. It is then very handsome, the back being yellow but 

 marked with three black stripes running nearly the length of 

 the wing covers. The length of the insect is scarcely a quarter 

 of an inch ; but the pest is so abundant in spring that serious 

 damage is inflicted if no steps are taken to prevent injury. 



Treatment. The more difficult it is to destroy an insect, the 

 more remedies are recommended, and the very number of these 

 is good evidence that none are specifics. Powders have gen- 

 erally been recommended for the destruction or disposal of the 

 two insects above described. Tobacco powder, or dust, is per- 

 haps the best of these, especially if a little carbolic acid be 

 added to it. The powder may be applied freely to the plants, 

 and applications should be repeated at intervals of a few days, 

 selecting a time when the plants are wet. In place of the 

 above, it has been recommended to use lime, plaster, road-dust, 

 etc., and kerosene may be substituted for carbolic acid. The 

 arsenites, when used dry and mixed with some of the above, 

 may also possess considerable value. All application should be 

 made early, and, if possible, to the under side of the leaves. 

 Spraying has not yet proved satisfactory. 



Plants are frequently protected by means of a device consist- 

 ing of a light frame, as two pieces of barrel-hoops crossing each 

 other at right angles, covered by some fine mosquito netting. 

 The frame is placed over the young plants, and over this is 

 spread the netting. The edges of the latter must be well 

 covered with earth, else the beetles will succeed in entering, 

 and when once under the netting it appears to be impossible 

 for them to get out again. When the plants have made a good 

 growth the screens may be removed. 



