Pinyon Trees Under Attack by Ips Bark Beetle

A site visit by Steve McKelvey and Richard VanDemark of the Arizona Department of Forestry and Fire Management on Thursday, March 21, 2019 confirmed what we already knew: our pinyon trees are under serious attack by the Ips Bark Beetle. Numerous trees to the south of LV Ranch have been killed by Ips and the invasion appears to be moving north into LV Ranch Estates.

The pinyons most vulnerable are those already stressed by Pinyon Needle Scale, drought, or micro-environmental changes (e.g., soil disturbance) but healthy trees may also be susceptible. While it may be impossible to protect all pinyons in LV Ranch, you may be able to save select healthy desirable trees (e.g., near your home). Here is some information that might help:

• Ips Bark Beetle (University of Arizona)

• Bark Beetle (USDA Forest Service)

• Bark Beetles (Arizona Department of Agriculture)

• Bark Beetles F.A.Q.

• Pheromone Repellant for Bark Beetles

If you have an infected tree, your only recourse to prevent the spread of Ips to other nearby pinyons is to cut down the infected tree and either burn or cover the wood with plastic. If you need help with mitigation efforts, contact either Steve McKelvey or Richard VanDemark (see contact info below); Arrow Fire and Land Management Company (David Bowden, 928.713.9085) may also be able to help.

Pinyon Needle Scale

As in most years, we can expect pinyon trees in Las Vegas Ranch to be attacked by pinyon needle scale (PNS). As noted in these two articles , these sap-sucking insects kill the needles and can seriously weaken pinyon pines:

• Pinyon Needle Scale (US Forest Service)

• Pinyon Needle Scale (The University of Arizona)

The good news is that you can easily mitigate the damage to your pinyon trees by reducing the infestation rate. Click here for information on how to do it.

Pitch and Bark Moths

Ips Bark Beetle Pinyon Needle Scale are not the only insect that can damage our pinyon trees:

• Pitch Moths

• Bark Moths

The good news is that at the current level of infestation, none of the above insects should kill pinyons.

For more information about the management of pinyon-juniper woodlands, click here for an excellent article from Colorado State Forest Service.

Contact Information

Steve McKelvey
Forest Health Specialist
Forest Health | Urban and Community Forestry
Arizona Department of Forestry and Fire Management
1110 W. Washington St., Suite 100
Phoenix, AZ 85007
Office: 602-771-1415 Cell: 602-647-5986
SMckelvey@dffm.az.gov

Richard VanDemark
Northwest District Service Forester
Arizona Department of Forestry and Fire Managemnet
1133 West Road 3 North
Chino Valley, AZ 86323
Office: 928-778-9567 Cell: 928-460-9311
rvandemark@dffm.az.gov