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CHAPTER XII. 



INSECTICIDES AND GENERAL REMEDIES. 



When dealing with forest insects and showing them in the cabinet 

 or life-history cases from an educational standpoint, one is generally 

 asked the question by practical men, What is the best way of getting 

 rid of them ] It will have been noticed that throughout the whole 

 of this work general and not specific remedies have been given. As 

 regards the latter, or the insects considered, it will be obvious that, 

 while there are some very notable exceptions, as a general rule only 

 sickly or back-going trees are usually attacked. Hence it is apparent 

 that there are two practical methods to be adopted viz. : (1) to main- 

 tain good health or encourage vigour either for trees or shrubs individ- 

 ually, and for woods or plantations when considered collectively ; and 

 (2) that where we do get certain insects attacking healthy trees in 

 nursery or plantation, special remedial measures must be adopted. 



With regard to good cultivation, it may be said that in making the 

 following remarks it is not intended that the methods should be 

 usually adopted in order to lessen insect attacks ; but, at the same 

 time, it is certainly true that in many cases bad methods of cultiva- 

 tion, together with careless workmanship or inattention to details, are 

 points very much to the advantage of insects. Hence the absence 

 of insects and good husbandry are often very closely associated. It 

 will perhaps be most practical to consider what may be done in the 

 nursery, the young plantation (ornamental or commercial), the middle- 

 aged wood, or in old woods prior to replanting. 



As regards the nursery, more especially the estate nursery, for gen- 

 eral plants the first thing to consider is the selection of a good site. 

 The nursery should not, e.g., be in the neighbourhood of an old Scots 

 pine wood or where Scots pine branches are likely to lie unburned 

 after heavy falls, as this would endanger young Scots pine or Austrian 



