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
Collecting Spot Expansion Data
Is the new spot you have located a threat to grow larger? It may well be. The southern pine beetle can readily spread if it has three conditions: Attractants from stage 1 trees, continuous emergence of attacking adult beetles from stage 1 and stage 2 trees, and pine to attack (fig. 17). During the summer, spots with no stage 1 trees are not likely to expand because attractants are no longer present. And spots with only stage 3 trees – since beetles have already left – need no control at all. The following steps, to be used between May and October, explain how to collect information for use in the control priority guide:
Walk completely around the spot and look for stage 1 trees, which indicate the area of most recent beetle activity. Areas with stage 1 pines are called "active heads". Check to see if the spot is expanding in more than one direction. Large spots can have more than one active head.
Determine the number of stage 1 and 2 trees.
For large spots that have more than 50 trees, it is not necessary to examine each tree. Just walk the boundaries and estimate the number of these trees in the spot.
From a location about 20 feet in front of the active head or heads, determine the pine basal area (a measure of stand density) in square feet per acre. A 10-factor prism is useful for this purpose.
Note whether most trees in the spot are pulpwood (less than 9 inches in diameter) or sawtimber size (more than 9 inches in diameter).
Using the Control Priority Guide from the next section of this handbook, determine the control priority for the spot.
Flag a trial back to the nearest road or landmark for the control crew.
Developed by the University of Georgia Bugwood Network in cooperation with USDA Forest Service - Forest Health Protection, USDA APHIS PPQ, Georgia Forestry Commission, Texas Forest Service
and the Pests and Diseases Image Library - Australia
Last updated on Monday, July 31, 2006 at 01:35 PM
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