Elm Savers


Elm Leaf Beetle

Is Elm Leaf Beetle an ongoing problem?
A: At this stage it appears to be the case.

Greg Lefoe a research scientist from the Keith Turnbull Research Institute has been researching the parasitic Tachinid fly (erynniopsis antennata), which was released on 29 January 2002.

If successful this parasite will reduce beetle numbers, but even in the best-case scenario trees will still need chemical treatment.

The fly represents another potential tool in an Integrated Control Program, but biological assisted control is some time off and may fail or be ineffective in our environment. Update as of April 2003 no survivors located in the field, trials will continue next spring with fresh releases., recent updates 2006/2007 appears to be the same.

The parasitic wasp (Tetrastichous gallerucae), released between 1990 and 1992, failed to parasitise eggs in trial areas; and survival of this parasite in the field and its impact has yet to be determined.

Further information: www.globalgarden.com.au

Treatment & Control

If my neighbour’s tree is untreated how will it affect my treated tree?
A: Your neighbour’s trees will be damaged but the trees that are closest to your tree will suffer least. Your tree will still have some shot hole caused by adult beetles but there should be NO larval damage.
How do I know my treatment is working?
A: In the warmer months tree-injected elms will start to bring adults down in as little as 8 minutes post treatment, but larvae can take between 30-45 minutes depending on the temperature.

Soil injected irrigated trees using the same chemistry take a minimum of 26 days to achieve the same outcome, larger trees at 100cm can take up 70 days.

Translocation and beetle kill times tend to be more uniform with tree injection, and no irrigation is required.

Read more about post treatment effects.

Beetles are still in my tree…is the treatment working?
A: Beetles only need to ingest a small amount of leaf material for the chemical to kill them; you will see dead and dying beetle on paved areas indicating that things are proceeding as planned. Further details about post treatment effects.

Tree vs Soil Injection

Should I soil inject my tree during a drought year with water restrictions?
A: Elmsavers has phased out the use of soil injection treatments in favour of more eco-friendly solutions. Trees generally have a better outcome when tree (trunk) injected as against soil injection.

Imidacloprid solubility is 610 mg to the litre which means that it won’t dissolve readily in water; a 100cm tree requires 92 litres of water to make the active ingredient soluble. Low moisture levels in the soil and its sub profile result in the precipitation of the active ingredient.

Soil injection requires high levels of moisture at the root zone for the active ingredient to dissolve; translocation to the leaf mass is ONLY possible when these conditions are met.

Soil injection is far more environmentally irresponsible as it wastes water and poses a significant threat to aquatic organisms: it kills earthworms at levels as low as 4ppm and it also is highly detrimental to micro-flora and mycorrhiza essential for tree nutrient uptake.

Elmsavers has phased out Soil Injection as of 2001

By using trunk injection method to treat your tree, you are avoiding the need to irrigate and rely on adequate rainfall as the chemical will translocate within the tree regardless of the moisture in the ground.

For further information please see our Tree vs Soil Injection Factsheet or go to Tree Injection and Soil Injection.

When should I soil inject my tree?
A: If you choose to soil inject your tree it can be undertaken in early March if the soil moisture conditions are right; this may give protection for the following 2 years.

In the past, Elmsavers’ extensive field trials have proved that early season applications have reduced adult damage when activity commences in late October.

Treatments can start in June but larger trees need early treatment, smaller ones can be taken right up to the cut off date.

Soil injection cease in the second week of October.

Please note, Elmsavers is phasing out the use of soil injection treatments in favour of more eco-friendly solutions such as tree injection. For further information, please read our Tree vs Soil Injection Factsheet.

How often do I soil inject my tree?
A: If your tree has been soil injected you need to treat it again prior to the third season, generally you can expect two years full protection from a soil injection treatment. We guarantee our treatment for two years. Trees that are untreated beyond this point may suffer severe damage in the third season.

Please note, Elmsavers is phasing out the use of soil injection treatments in favour of more eco-friendly solutions such as tree injection.

Are all trees soil injectable and what are my alternatives?
A: The answer is NO. – not all trees are soil injectable.

Trees with restricted root access are unsuitable including paved areas, driveways or waterways etc.

Furthermore, chemical applications near creeks and rivers can leach into the aquatic environment or groundwater with serious outcomes, as they are highly toxic to invertebrates.

What are the alternatives to soil injection?
A: Canopy spraying can successfully treat most of these tree ailments, except for trees near waterways.

Spraying needs to be done every year, and a single treatment is all that is required for complete protection for the whole season.

Tree injection (also known as trunk or micro injection) is the best long-term protection available. It efficiently uses the tree vascular system (xylem) to transport systemic chemistries.

Can anyone treat my tree?
A: Elmsavers strongly advises against non-professional or unlicensed people attempting to inject trees with insecticides.

Tree injection is a highly specialised field and it requires an acute understanding of organic chemistry and plant diseases. Chemistry applications that target specific disorders either insect or disease needs to be fully understood.

General Tree & Plant Health

In the event of an outbreak of Dutch Elm Disease in Australia, what are my options?
A: We do not have Dutch Elm disease in Australia. However, if there was an outbreak it would be wise to inoculate high value amenity trees as a precaution.

The disease – Ceratosystis Ulmi aka Ophiostroma Ulmi – is a fungus that damages the tree’s vascular system. The disease is spread by the Elm Bark Beetle (scolytus multistriatus).

We have taken a proactive approach to this threat; so we can respond immediately. Emergency hygiene protocols & registration of chemistries coordinated by the authorities would come into effect.

Treatments of this nature have been in place for many years overseas – trees that could have died are now thriving.

Elmsavers’ system of treatment is fast and efficient; we can treat a large number of trees if necessary, and it is superior to methods used in the USA in delivery time of the active ingredient. The New Zealand experience has shown that elimination of the pathogen is unlikely. Authorities in the past claimed eradication only to find fresh outbreaks occurring.

Contact us for further information on any of these issues.

Elm Savers Factsheet
Read and download our factsheets on pests, diseases and treatment methods