• Cypress Bark Beetles

      Schalau, Jeff; Entomology (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2003-06)
      Cypress bark beetles are native insects that often impact ornamental Arizona cypress and Leyland cypress trees. Healthy, vigorous cypress trees can usually withstand substantial beetle pressure. However, significant mortality of host tree species often occurs during periods of extended drought. Tree vigor can easily be maintained through deep, infrequent irrigation during drought periods.
    • Guidelines for Thinning Ponderosa Pine for Improved Forest Health and Fire Prevention

      DeGomez, Tom; Natural Resources & the Environment, School of (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2006-03)
      Preventing catastrophic stand replacing events are best accomplished through thinning. Lower tree densities result in greater tree growth. Stands with lower tree densities have greater plant diversity. Determining stand conditions will provide a baseline for formulating a plan to improve stand conditions. Thinning around individual trees can improve individual tree health reducing the likelihood of damage from bark beetles, fire or drought.
    • Insects, Diseases and Abiotic Disorders in Southwest Forests and Woodlands

      DeGomez, Tom; Garfin, Gregg (College of Agriculture, University of Arizona (Tucson, AZ), 2015-11)
      Recent events in the forests of the Southwest, and across western North America, have prompted scientists to consider the role of climate variability in insect and disease cycles. Studies focusing on Arizona and other southwestern states point to multiple, interacting climate-related mechanisms that increase the propensity for forest mortality. Effects of insects on forests are complex, and species and site dependent. Many influences, such as drought, decreased precipitation, increased temperature, increased vapor pressure deficit, and increased stand density, combined in nonlinear and overlapping ways to create the recent and devastating pine bark beetle outbreaks in Arizona forests. Climate clearly plays a role in many, but not all, Southwest insect cycles. It is important that educators demonstrate the complexity of all of the interplaying issues, in order to communicate no false impressions of an “easy” or “one-size- fits-all” solution” for land managers.
    • Insects, Diseases, and Abiotic Disorders in Southwest Forests and Woodlands (Climate Change and Variability in Southwest Ecosystems Series)

      DeGomez, Tom; Garfin, Gregg; Natural Resources & the Environment, School of (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2006-08)
      Recent events in the forests of the Southwest have prompted scientists to consider the role of climate variability in insect and disease cycles. Over 70 million pine trees along with millions of other conifers died in 2002-03. Average temperature increases of 3°C enabled the MPB at those high elevations to achieve univoltine (having one generation per year) reproduction leading to previously unheard of outbreaks in white bark pine at high elevation sites in Idaho.Aspen defoliation in Arizona and New Mexico averaged ~ 20,375 acres from 1990 to 1997. A series of events has contributed to the decline of aspen since 1997.
    • Pine Bark Beetles

      DeGomez, Tom; Young, Deborah; Entomology (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2009-05)
      This paper provides evidence of the infestation caused by pine bark beetles in Arizona. It provides information about their life history, and how to prevent and control them.