Pine shoot beetles active in Scotch and Austrian pine

Now is the time to scout Scotch and Austrian pine fields for the new generation of pine shoot beetles. Adults can be found feeding in tunnels down the center of new or 1-year-old shoots.

The new generation of pine shoot beetles (Tomicus piniperda L.) can be found feeding in tunnels in the center of new or 1-year-old shoots on various pine species. They will spend the rest of the summer feeding in the shoots.

The reddish-brown to black adult beetle (Photo 1) will feed in tunnels down the center pitch of the shoots. These tunnels are hollow and are not filled with frass. Now is the time to check fields for evidence of shoot-feeding beetles. Look for broken branches, needles on the tips of branches turning brown, and a round hole on the outside of the shoot which is often surrounded by pitch (Photo 2). Some shoots will have only one tunnel while others may have several short tunnels. Infested shoots generally bend near the point where the beetles entered, turn yellow to red, eventually break off, and fall to the ground (Photo 3). As you find these branches, clip them out and remove them from the field.

Pine shoot beetle adult
Photo 1. Pine shoot beetle adult. Photo credit: Steve Passoa, USDA APHIS PPQ, Bugwood.org.

Tunnel opening
Photo 2. Tunnel opening surrounded by small glob of pitch.
Photo credit: Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org.

Scotch pine showing flagged shoots
Photo 3. Scotch pine showing flagged shoots.
Photo credit: E. Richard Hoebeke, Cornell University, Bugwood.org.

Did you find this article useful?