In southeastern Colorado, Pinus edulis (Piñon) and Juniperus monosperma (One-seed juniper) are part of the native landscape and we often look at them as indestructible. Unfortunately, our piñon are under attack by an insect that most of us didn’t know much about until two years ago. The damage caused by piñon pitch mass borer in natural areas and local landscapes has been devastating.
I’ve personally visited more than 30 sites in various parts of Pueblo County where one or more piñon showed symptoms of piñon pitch mass borer (Dioryctria ponderosae). The Colorado State Forest Service office in Cañon City reported that they have seen infested pines in Fremont County and a local rancher says he has found evidence of infested piñon in northern Huerfano County. While the problem is primarily on piñon, I’ve found evidence of the insect on Ponderosa (Pinus ponderosa) in landscapes in Pueblo West. In the Midwest, the European native Scots (Pinus sylvestris) and Austrian (Pinus nigra) pines have also been attacked, but we haven’t seen piñon pitch mass borer on those species in Pueblo as of early 2013.
Many pines are overwatered in urban landscapes, making them more susceptible to pitch mass borer due to excessive succulent growth or bark cracks. And while many of the plants I’ve examined are in landscapes, others are in unirrigated natural areas. Those trees are likely weakened due to the continued drought in our area.
|Fresh and dried pitch on Pinus edulis. |
Photo by CMG Sylvia Sanchez.