Today's post for National Invasive Species Week highlights two ambrosia beetles that are detrimental to certain trees. Ambrosia beetles are highly specialized beetles that excavate tunnels in usually weakened or dead trees and cultivate fungal gardens, which they feed upon. Below are two such invasive beetle-fungal complexes that are currently impacting trees and forests in California.
Walnut twig beetle and thousand cankers disease. Walnut twig beetle, Pityophthorus juglandis, is a tiny bark beetle that attacks only walnut trees. The beetle has been in California for many decades but recently became associated with a new fungus, Geosmithia morbida. The fungus kills the phloem and cambium of...
- 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...