Show PROLIFIC BREEDER IS BEETLE enemy of pine timber only kept in check by strenuous natural and artificial control special study has been made of the number of all stages of the western pine beetle in square feet of infested bark selected from 67 trees which represented nn an average infestation within an area of approximately 36 square miles says the american forestry magazine it Is shown there la Is a large percentage of mortality between the young and matured stages in the developing broods but that normally mally an average of about beetles to the square foot of bark developed to the adult or reproductive stage which would be beetles to the average infested tree or say beetles to 1000 board feet of timber S since ince it requires an average of about te ten n beetles to the square foot to attack and kill a vigorous healthy tree it will be seen says the america Ame forestry association which is campaigning pai gning for a natio national nill forest policy that all the pine timber of the western forests would soon be destroyed were it not tor for natural and artificial control |