PEOTECTIOK AGAINST ANIMALB. 137 



by 87 ; black-walnut by 11 ; butternut by 18 ; chestnut 

 by 18 ; locust by 30 ; maple by 37 ;. bircli by 19 ; beecli 

 by 15 ; tulip-tree by 9 ; pines "by 103 and spruces by 34. 



Besides enumerating and describing those insects the 

 bulletin also contains an account of the remedies to bo 

 applied in destroying them. But the average forester 

 will seldom be able to make use of them, ihey being too 

 expensive and causing too much labor in extensive for- 

 ests. If large tiacts in the forest are taken hold of by 

 insects, we have to decide which parts can still be saved, 

 and then apply every means to suppress the pest. But 

 if it has spiea'l to such a degree that humim help can- 

 not more be of any use, the afflicted trees have to be cut, 

 aud if possible to be disposed of as wood products, or, 

 if that is not praciicable, the torch has to be applied to 

 tliem with proper precaution against spreading of the 

 fire beyond the limits of the infested tract. After the 

 fire has destroyed the insects, larvae and eggs, the de- 

 nuded area should be reforested at once, in order to 

 close the opening made in the forest as soon as possible, 

 and to prevent the elements from making inroads upon 

 the opened forest. 



Jn the same proportion as the species of forest-trees of 

 Ihis country greatly outnumber those of Europe tlie in- 

 sects detrimental to them are here more numerous than in 

 Europe. But the damaging influence of the in ects here 

 upon forest-growth has not been so generally injurious 

 on account' of the diversity of trees growing in our wild 

 or natural woods, where insects may feed undisturbed 

 upon certain trees preferred by them ; and for the exten- 

 sivity of our forests, where the damages of the several 

 species of insects may be not so remarkable on the single 

 trees ; both circumstances furnishing at the same time 

 very good opportunities for creating in large immbers the 

 natural persecutors of obnoxious insects. However, we 

 should not be careless in this matter as not only in our 



