IMPATIENS INSECTS 135 



greenhouse or a room. It is readily propagated from seed or 

 cuttings, seed being preferable. Flowers bright pink - red. 

 Of easy culture in a fairly moist atmosphere. Height about 

 18 inches. 



Insects. For horticultural purposes, Insects 



might be grouped into three general classes : borers, or those 

 which live inside the plant tissue ; chew- 

 ing Insects which live on the outside of 

 the plant; and the sucking Insects. 



As a general statement, it may be 

 said that the digging out of borers is the 

 only complete remedy. Sometimes an 

 application of something to the body of 

 the tree may keep them out, but it is al- Moth of one of the borers 

 ways uncertain ; and it usually involves more work than to 

 dig them out. All trees which are subject to borers (espe- 

 cially apples, peaches and pears) should be examined at 

 least twice every year. See Borers. 



The general run of chewing or biting Insects may be 

 killed by the arsenical poisons. Such Insects are the com- 

 mon types of worms and beetles which feed on foliage. The 

 leading poison which is now used for this purpose is Paris 

 green (which see). Hellebore and pyrethrum are useful 

 when it is not advisable to use arsenical 

 poisons. 



The sucking Insects include all the kinds 

 of plant lice, the squash bug and all the 

 scale Insects. These are dispatched by 

 some material which kills by external appli- 

 cation, especially material which has kero- 

 sene or petroleum in it. The common ma- 

 A beetle borer terial heretofore used for this purpose is 



kerosene and soap emulsion ; but it is now believed that the 

 emulsion of kerosene and water is fully as efficient, and since 

 machines have been perfected for automatically mixing it, it 

 is a much more practicable remedy. See Kerosene Emulsion. 



