Host:
Most pine species (primarily Austrian & Scotch pine).
Identification:
Globs of resin on trunk (at “whorl”) where branches
join the trunk.
Damage:
The caterpillar stage causes the resin by tunneling
around the “whorl” weakening junctions. Branches
break off in the wind or snow storms resulting in
poorly shaped trees.
Control:
One application each year will help prevent borer
reinfestation. Infested trees will continue to be
attacked if left untreated.
What to expect/checking control:
The globs of resin will remain on the tree for several
years. Over time, the globs of resin will become
discolored, hard and fall off, indicating control.