Zimmerman Pine Moth

What is Zimmerman Pine Moth?

Zimmerman Pine Moth (Dioryctria zimmermani) was first detected in the US in 1879. Austrian and Scots pines are preferred hosts of Zimmerman Pine Moth. However Eastern White and Mugo Pines are also attacked.

What does Zimmerman Pine Moth look like?

Adult Zimmerman pine moths are midsized with gray and red-brown wings, marked with zigzag lines. Larvae are generally dirty white to light grey and up to one inch long. They can only be found in pitch masses, under bark or in new shoots.
Zimmerman pine moth larvae tunnel into new growth causing shoot dieback, or into whorl areas causing masses of pitch to form at the wound site. Repeated attacks by the larvae cause a weakening at the area of the infestation and make the branches and trunk susceptible to breakage.

How do you control Zimmerman Pine Moth?

Avoid plant injury (e.g., construction injury) and environmental stresses (e.g., drought stress) that can make trees attractive to Zimmerman pine moth adults. Applicants must be made in the spring, before larvae migrate into tree trunks. Preventive insecticide sprays should be applied as a drenching spray to trunks in mid to late April. Sprays are also made in early September to kill small larvae.