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.