162 INJURIOUS INSECTS OF 1903. 



cylinder surrounding each plant and planted a few inches (2 or 3) 

 in the soil. Poisoning bundles of clover with a solution of Paris 

 Green and strewing the same amongst the plants to be protected 

 is one good method. Both of these the Entomologist has tried 

 with some success. Paris Green, it must be remembered, is a 

 slow acting poison comparatively, and one must not expect 

 worms which have eaten it to die at once. Planting an excessive 

 number of seed or plants is sometimes resorted to. The writer 

 has found the guilty worm frequently concealed an inch or two in 

 the soil in the morning, not far from the plant injured during the 

 night. He has also trapped them successfully by placing cab- 

 bage leaves, or any large leaf or board, among plants needing 

 protection, finding the worm under there in the morning. See 

 also page 70. 



POTATO BEETLES. • 



Complaint reaches this department to the elTect that sprink- 

 ling potato plants with Paris. Green for this pest doeS not give 

 satisfactory results, either failing to kill the beetles or, if eflfica- 

 cious in this, injuring the foliage of the plants. While this burn- 

 ing may be in part due to an excess of arsenic in poor Paris 

 Green (see article on page 33), it may be the result of improper 

 mixing and application. One pound of good Paris Green in 150 

 gallons of water (or a smaller quantity of the poison and water 

 in the same proportion) should do good work if frequently 

 stirred while being used. It must be borne in mind that Paris 

 Green settles rapidly in water, and the liquid should be kept 

 stirred ; otherwise the plants or trees receiving the liquid from 

 the bottom of the containing vessel will be badly burned. A 

 quart of lime water, or of ''milk of lime," poured into a pailful 

 of the Paris Green mixture, will help prevent the burning. 



In this connection we must mention arsenate of lead, see 

 page 99, which can be used practically any strength without 

 injury to the foliage. 



EXPERIMENTS WITH COCKROACHES. 



As a result of some personal experiments against these pests 

 the Entoipolog'jst J5 prepared to pnrJpfse the vjse pf borax against 



