Elm Savers

Fruit Tree Borer is a Spreading Threat to Elms

The fruit tree borer is a serious pest is in regards to ornamental and native trees, with a preference for black wattles, it has quickly adapted to the softer and sweeter wood of exotics. It is a known pest of over fifteen species of trees and vines with damage now seen in Golden, English and and Dutch elm cultivars, Oriental Plane trees and a number of Oak, Maple and Birch species.

Standard methods such as soil injection and canopy spraying with Imidacloprid have been ineffective in controlling this pest. Fruit tree borer and other lepidopteran insects have a very high tolerance to Imidacloprid insecticides, and are ineffective, regardless of formulation or delivery method.

At treatment May 1st 2007 note Frass on trunk New callous tissue is evident on June 17th 2008
At treatment May 1st 2007 note Frass on trunk New callous tissue is evident on June 17th 2008

Proof of Effect


Image on left: Before treatment, fruit tree borer damage in Golden elms can be very extensive to the point of ring barking the entire trunk and killing the tree.; Image in middle: During treatment, tree Recovering; Image on right: After treatment


Cato Park Northern Grampian Shire. Image on left shows fruit tree borer old damage and new callous growth. Image on right shows improvements one year on.

Read our fact sheet on Fruit Tree Borers.