A Field Guide for Ground Checking Southern Pine Beetle Spots

Southern Pine Beetle Handbook

United States Department of Agriculture
Combined Forest Pest Research and Development Program - Agriculture Handbook No. 558 - Issued November 1979

Seasonal Variation in Attack Symptoms

The time it takes SPB to grow from eggs to adults varies seasonally, as does the time it takes for symptoms of beetle's attack to appear in infested pines.  Judging the presence or absence of SPB and the stage of development during the winter months can be a difficult task. Foliage on trees attacked in cold months may remain green for long periods, although such trees quickly lose their needles once foliage discoloration begins.  Because the beetle needs 2-4 months to mature during cold months, some winterkilled pines with bare crowns may still contain SPB. Also, the insects in winter often reattack the top and base of a tree already containing developing broods.  This leaves different beetle life stages at different heights in the same tree. Because of these difficulties, no attempt has been made to categorize infested spots for the winter months.

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