CONE BEETLES. 11 



CONDITIONS REQUIRING CONTROL. 



Since these insects are not a menace to growing timber, their con- 

 trol by direct expense is desirable only where it is found to be se- 

 riously interfering with the natural or artificial reproduction of the 

 host tree. Under the conditions of the mature, well-stocked stands 

 prevalent in the virgin forests of the West it is very doubtful 

 whether the beetles ever interfere with the required natural repro- 

 duction to an extent sufficient to require artificial methods of control. 

 Seldom is the entire crop killed and eventually through a period of 

 years sufficient good seed is produced to replace the normal loss of 

 trees from lightning, light fires, normal insect infestation, and over- 

 maturity. However, conditions are entirely changed when the 

 virgin forest has been destroyed by timber cutting, fire, or epidemic 

 insect infestations. Yellow pine and sugar pine are rated as two 

 of the most desirable timber species, and if the restocking of areas 

 denuded of these species is to be accomplished by natural reproduc- 

 tion, full seed crops must be produced by the seed trees left on or 

 near the areas. If the cone crops of such yellow and sugar-pine 

 seed trees are repeatedly destroyed by the cone beetles, or if these 

 infest them to such an extent that the destruction is completed by 

 rodents, then the required seeding may be delayed until the ground 

 is usurped by less valuable tree species. Under such conditions 

 measures which will reduce the infestation of the beetle by direct 

 expense may in the end effect a saving in the conservation of the 

 forest. If burns or cut-over areas are restocked by artificial seeding 

 the collection of sound, mature seed is necessary. Again, we may 

 find that the cone beetles have so reduced the supply of cones on 

 selected seed-collecting sites that seed can not be profitably collected. 

 In the last case damage may be avoided by intelligent selection of 

 noninfested seed-collecting areas. Or if the site is selected a year 

 in advance^ the infestation may be reduced and most of the seed 

 crop saved by application of the remedy. 



REMEDY. 



From the discussion relating to the seasonal history of the insect 

 it is obvious that from the last of August until the following May 

 all the infestation within an area will consist of the broods of new 

 adults which are overwintering within the blighted cones. It is evi- 

 dent that if fallen infested cones from the trees which seed in a 

 burned or cut-over area can be raked up and burned between Sep- 

 tember 1 and May 1 a very appreciable reduction of the infestation 

 and damage may result. In the case of sugar pine all infested cones 



