Elm Leaf Beetle Treatment

Elm trees are subject to infestation by the Elm Leaf Beetle (ELB).  The beetle and its’ larva are responsible for extensive defoliation throughout the Elm populations of Victoria.


Life cycle:

The beetle makes a few small ‘shot holes’ in the leaves when it comes out of hibernation.  It then lays eggs below the leaf.  The eggs hatch and a small caterpillar digests all except the skeleton of the leaf.  Most of the tree damage is caused at the larval stage.  The larva then crawls down the trunk to pupate into an adult beetle and start the process again.


Attempts have been made to control the beetle by painting general insecticides onto the trunk, and by creating a sticky surface around the trunk.  This was found to have a limited effect, as it will only catch the larvae as they migrate down the trunk.  It will not prevent the larvae from skeletonising the tree.  Other trials on canopy spraying gave beneficial results but lasted less than a full growing season.

The most suitable ELB protection that is presently available for your tree is soil injection and stem injection.

Soil injection

A soil probe is pushed into the ground surrounding the tree at several sites and a low-toxicity systemic insecticide is pumped into the injection hole.  The tree takes the insecticide up through its root system.  The beetle ingests the insecticide as it feeds on the leaves.  One of the major benefits of this application technique is the elimination of the need to aerial spray.  The transport of the insecticide is carried out below the soil and within the tree itself.

The soil injection technique can have a beneficial effect for several seasons.  The length of time that the protection will last depends on many factors within the environment.  To monitor the effectiveness of the treatment we make annual inspections of all the Elm trees that we treat.  The only evidence of beetle attack should be a few shot holes from the adult beetle.  Your tree effectively becomes a giant trap for Elm Leaf Beetle.

Stem injection

Stem injection offers similar results to soil injection.  One advantages of stem injection is the localised dosage.  This means there is less chemical used in the treatment and we don’t need access to the whole root system.  Some trees have roots in neighbouring properties where we cannot gain access or even roots under paved surfaces such as roads and paths.  Stem Injection only requires access to the main trunk.

The downside to stem injection is its invasive nature.  We need to drill several holes in the trunk to administer the dosage.

Treatment prices for soil of trunk injection:

Price is determined by the trunk diameter of the tree.  We measure the trunk diameter at 1.5 metres above the ground or just below the first fork if there are multiple stems.

Single tree less than 40cm $180Single tree 40 to 80cm $240Single tree 80 to 120cm $280Single tree 120 to 150cm $320plus $30 for every additional 10cm of trunk width.


Up to ten additional trees on your land or a neighbouring  property: Less 20% on total price
More than ten trees: P.O.A.
Prices exclude G.S.T.