The Southern Pine Beetle in Pennsylvania(Dendroctonus Frontalis Zimm.)

Abstract

The southern pine beetle has increased in southern Pennsylvania since 1930 owing to mild winters and hot, dry summers. Slowly growing, over-ripe, fire-scorched, windfall, or lightning-struck trees suffered most from attacks. Temps. below 10[degree]F. for short periods resulted in high mortality to larvae, especially those overwintering in the phloem. Mortality was least in thick-barked pitch and shortleaf pines and greatest in table mountain, white and Virginia scrub pines.