174 The Farm Woodlot 



expensive. The banding of the trees with tanglefoot is 

 also successful hi the case of isolated trees, but the bands 

 must be constantly watched to see that they do not be- 

 come covered with dust, webs or dead caterpillars. De- 

 struction of the pupae in June and early July is usually 

 accompanied by severe poisoning. 



The pine-destroying beetle of the Black Hills 



This pine beetle (Dendroctinus ponderosd) , is one of the 

 most active and destructive insects in the West and has 

 already ruined large areas of timber in the Black Hills. 

 It is not, however, of very great importance from one 

 point of view, because the bull pine, the species most 

 subject to its attacks, is not very well adapted to woodlot 

 growth. 



Hopkins describes the adult as "a stout, dark brown 

 to black beetle, individuals of which vary in length from 

 about i to J inch." 



The presence of the insect may be discovered by the fine, 

 powdered dust sifting down the trunk of the tree. It 

 first appears in August, when the adult beetles settle on 

 the trees in swarms, and start their galleries, the resin and 

 sawdust being pushed out of the opening where they form 

 pitch tubes around the holes. These galleries are usually 

 almost straight cut in the soft inner bark, often grooving 

 the wood, and the eggs are laid in th'e notches along the 

 sides. When the larvae hatch they start side galleries, 

 at right angles to the primary gallery, that increase in size 

 as the larvae grow. At the end of this gallery the full- 

 grown larvae dig a widened cavity in which pupation 

 takes place. The adult digs from this cavity through the 



