[From the December 2014 issue of the UC IPM Green Bulletin]
For at least a decade, thousand cankers disease (TCD) has been killing walnut trees across California wildlands and landscapes. The causative agent is a yeast-like fungus (Geosmithia morbida) spread by a tiny native beetle called the walnut twig beetle (Pityophthorus juglandis) (Figure 1). TCD has killed thousands of walnut trees and threatens not only ornamental and landscape trees but also English walnut trees in commercial orchards. Once a tree becomes infected no control is available; therefore, it is.../span>
- Author: Mary Louise Flint
[From the April 2014 issue of the UC IPM Green Bulletin newsletter]
Over the last several decades dozens of exotic pests have invaded California landscapes, causing at least temporary havoc and sometimes severely affecting the aesthetic value of plants or even killing them. Giant whitefly, hackberry woolly aphid, eucalyptus red gum lerp psyllid, Diaprepes root weevil, myoporum...