28 INSECTS INJURIOUS TO VEGETABLES 



made by cutting a barrel hoop in two so as to form two semi- 

 circles, which are then placed at right angles to each other, and 

 the lower ends inserted into the ground with the curve upper- 

 most. This is then covered with gauze or similar material, held 

 in place with earth packed about the edges, to prevent the 

 beetles working under it. It is necessary to keep the plants 

 covered only while they are young, and the same covering may 

 be used year after year. Such covers are much used against 

 the striped cucumber beetle, and radishes have been successfully 

 protected from root-maggots. 



Trapping. — Several methods of trapping insects are practiced 

 with success. Trapping under boards, shingles, chips, etc., is 

 useful for squash-bugs and cutworms and if employed properly 

 will serve as a means of destroying many pests. In the case 

 of cutworms poisoned baits are placed under such traps. 



Pruning and the destruction of affected parts, practiced with 

 benefit against many tree-borers, are useful methods for killing 

 some vegetable feeders, c. g., aphides or "lice" when congre- 

 gated on seedstalks of crucifers, etc. 



Miscellaneous mechanical remedies. — Such remedies as ditch- 

 ing, disking and driving are applicable to only a few forms of 

 insects and will be mentioned in the body of the present work as 

 remedies for those insects where described. Ditching is prac- 

 ticed against the army worm, as is also di.sking, and such insects 

 as blister beetles and cucumber beetles may be driven by various 

 means from cultivated fields. 



Repellents. — Various substances have been advised in the past 

 and are claimed by "knowing ones" to be valuable as preventives 

 of insect attack, but comparatively few deterrents will stand a 

 thorough test The best for use on vegetable crops will pres- 

 ently receive mention because of their value as insecticides or 

 fungicides. These are: Tobacco; carbolic acid, used in emul- 

 sified form ; Bordeaux mixture ; kerosene emulsion ; sulphur, 

 when freshly applied ; and fish-oil soaps. Certain substances like 



