CHAPTER XIV 



THE PROTECTION OF WOODLANDS AGAINST INSECT 

 ENEMIES 



Sylvicultural Entomology, a branch of the Protection of 

 Woodlands thoroughly taught at all the Universities and 

 Academies in Germany which provide for instruction in Forest 

 Science, relates not only to the injurious Forest Insects, but 

 also to the useful species which prey upon these and tend to 

 restrain their increase in large numbers likely to damage the 

 growth of timber crops. Under noxious Forest Insects gene- 

 rally, all the species which may perhaps be found at any time 

 on woodland trees are not included, but merely such as occur 

 more or less frequently in large numbers, and do perceptible 

 damage to the growth and development of the timber crops. 



The nature of the injuries inflicted on woodland crops by 

 insect enemies is manifold ; and neither the seedling growth, 

 nor the young pole-forest, nor the mature crop, is safe from 

 injuries varying from slight attacks on foliage, bark, and roots, 

 occasioning merely temporary disturbance, up to the total 

 destruction of crops over enormous areas. Even when exten- 

 sive devastations do not take place, both young crops and trees 

 may be so seriously disturbed in normal growth, as to occasion 

 loss of increment, and the formation of blanks necessitating 

 outlay for re-filling and improving. 



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