26 FOREST PROTECTION' 



VIII. Remove or poison stumps if they are found to form the incu- 

 bators or food-objects of a noxious insect during one of its 

 stages. 



IX. Peel off the bark where logs are left on the ground for any- 

 considerable length of time. 



X. Encourage hog pastures in the case of certain species of in- 

 sects. With other species, steep walled ditches may prevent 

 the enemy from spreading in nurseries and plantations. 



XI. Protect the insectivorous animals, notably: — 



a. Bats, moles, weasels, foxes, etc. 



b. Woodpeckers, tits, owls, etc. 



c. Amphibia. 



d. Spiders. 



e. Centipedes, millipedes, etc. 



XII. Collect and destroy the insect in that stage which best allows 

 remedial measures to be taken. 



a. Eggs may be tarred or covered with creosote when 

 they are placed in masses in conspicuous positions. 



b. Larvae may be destroyed by spraying the food plant 

 with arsemcals or other stomach poisons, or the in- 

 sects themselves with kerosene or other contact poi- 

 sons; by trapping them on or below bands of burlap 

 or tree tanglefoot; by the use of trap trees; or by 

 burning their winter quarters or the object (bark) 

 forming their abode. 



c. Pupa* may sometimes be collected and burned, par- 

 ticularly when the insect hibernates in this stage. 



d. Adults may be beaten off the bushes during the early 

 morning; may be collected during the hot hours of 

 the day in artificial hiding places; or may be caught 

 by means of pit-falls, tanglefoot or burlap rings, trap 

 trees, or electric lights. 



The selection of a method of treatment depends not only upon 

 the species of insect concerned, but upon many factors enter- 

 ing into the local conditions. In general, prevention is better 

 than the application of a remedy. This is particularly true 

 in the present status of American forest conditions; and the 

 use of insecticides is only profitable in rare instances. Indeed 

 in America the forester will frequently be prevented from adopt- 

 %ng any measures whatever, remedial or preventive, because the 

 cost will exceed the value of the benefit to be derived. But in no 



