Elm Leaf Beetle Management Strategy

Alpine Shire Council

JULY 2003

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Background Information There are an estimated 7000 elms within the Alpine Shire alone, the majority of which have now been effected by the Elm Leaf Beetle. The Elm Leaf Beetle was discovered in Anderson Street, Bright on the 30th January 2001. The Elm Leaf Beetle (Pyrrhalta luteola) was first discovered in Australia in 1989 and is thought to have been accidentally introduced to the country from the northern hemisphere. It is a known hitch-hiker, therefore its spread along traffic routes is inevitable. The elm leaf beetle has the potential to cause severe defoliation of susceptible elms, which can weaken mature trees and reduce their aesthetic and amenity value. Elms suffering from repeated elm leaf beetle attack are also more susceptible to other pests and disease. Elm leaf beetles commonly hibernate over winter in and around buildings and can cause a nuisance when emerging inside buildings in large numbers during spring. A heavy infestation can cause a mature elm to be defoliated by mid-summer. The elm leaf beetle will never be eradicated from Australia, however control measures are available which will reduce beetle numbers and prevent serious damage. There is no reason for a well managed elm to be lost due to elm leaf beetle. (Lefoe, G. Look Out For Elm Leaf Beetle. (www.global-garden.com.au))

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Contents …………………………………… Background Information .........................................................................................2 Reasons for Shire Investment in Elm Leaf Beetle Management ..................4 Scope of the Elm Leaf Beetle Management Strategy ......................................4 Goal ..............................................................................................................................4 Aims .............................................................................................................................5 Stakeholders ...............................................................................................................5

Department of Sustainability and Environment.........................................................5 Alpine Elm Care Action Group .................................................................................5 Private Landowners ...................................................................................................5 Friends of the Elms ....................................................................................................5 Keith Turnbull Research Institute..............................................................................5

Management Strategies............................................................................................6 Strategy 1 Manage Elm Leaf Beetle through control programs ..................6 Strategy 2 Removal of low quality elm trees....................................................6 Strategy 3 Support and facilitate public education..........................................7 Strategy 4 Monitoring, Evaluation and Reporting...........................................7 Control Methods........................................................................................................7

Foliage Spraying ........................................................................................................7 Trunk Banding ...........................................................................................................7 Soil Injection..............................................................................................................8 Trunk/Stem Injection .................................................................................................8 Biological Control......................................................................................................8 Pruning Trees .............................................................................................................8

Contacts .......................................................................................................................9 Appendix 1a Bright Township ..............................................................10 Appendix 1b Bright Township 11 Appendix 2 Porepunkah Township 12 Appendix 3 Wandiligong Township 13 Appendix 4 Myrtleford Township 14 Appendix 5 Mount Beauty Township 15 Appendix 6 Harrietville Township 16

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Elm Leaf Beetle Management Strategy

Reasons for Shire Investment in Elm Leaf Beetle Management There are a large number of elm trees within the Alpine Shire that have high social and aesthetic value. Elms make up an important aspect of the Shires cultural landscape as they line our avenues and display autumn colour. The regional profile of our feature elms helps attract people to the region and is used in promoting the Shire. The effects of the elm leaf beetle could be seen as a visual indicator of the health of the region and impact on tourism in the area. This could have major impacts on the economic development of the Shire.

Scope of the Elm Leaf Beetle Management Strategy This strategy has been developed for the management of elm trees on land managed by Council and provides information to other authorities regarding the elm leaf beetle. With the high numbers of elm trees across the Shire, it would be an impossibility to manage every tree because of the high cost and the fact that many elms are on private property and not under the control of council. Council therefore prioritised individual trees to determine its management strategy. Trees were classified into three priorities; high, medium and low. High priority trees were categorised as:

• Major feature trees • High tourism value

Medium priority trees were categorised as:

• Valued feature trees • Trees not within main tourism areas

Low priority trees have been programmed for removal. These were categorised as:

• Trees outside township areas with little significance. • Small trees easily replaced. • Damaged or poorly formed trees. • Trees in inappropriate locations. • Self-sown or sucker growth.

Goal Minimise the impact of the Elm Leaf Beetle on trees managed by the Alpine Shire while providing information to; and encouraging program implementation for trees managed by private landholders and other authorities.

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Aims

1. Enhance high priority trees across the shire 2. Remove elm trees of low value 3. Educate and facilitate the public and other authorities to their responsibilities.

Stakeholders Department of Sustainability and Environment The Department of Sustainability and Environment (DSE) is the main State Government department responsible for the administration and management of Victoria’s resources and public land and waters. DSE have responsibility for elm trees located on crown land. A partnership needs to be developed with DSE to encourage program implementation. At this stage, because elms are exotic the Department places a management program as a low priority. Alpine Elm Care Action Group The Alpine Elm Care Action Group is a voluntary group made up of community members with a strong commitment to Elm Leaf Beetle Management. The action group can assist with community education and the management of the beetle on private and public land. Private Landowners Elm trees located on private property are the responsibility of the landowner. For the Elm Leaf Beetle Management Strategy to be successful it is important that all elm trees within the shire are treated. Community education will therefore play a major role in successfully implementing the program. Private landowners need to make the decision whether they want to keep and treat their elms or have them removed. If left untreated, the landholder could find that their elm will receive greater infestations, which inturn, could result in the death of the tree. Friends of the Elms The Friends of the Elms Inc., is a State/National voluntary not-for-profit organisation which was founded in 1990 for the purpose of raising awareness to the importance of Elms and assisting to fund research into the potential threats of pests and disease Keith Turnbull Research Institute The Keith Turnbull Research Institute (KTRI) was established in 1967 to undertake research on a wide range of declared noxious weeds. The institute has since expanded to include research on vertebrate and invertebrate pest species and is dedicated to

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working with government, industry and the community to develop and implement integrated management techniques to address pest plant, animal and insect species across Victoria. Their expert, Mr Greg Lefoe has been consulted on appropriate management methods.

Management Strategies The following strategies will be implemented across the Shire in order to successfully manage the effects of the Elm Leaf Beetle.

Strategy 1 Manage Elm Leaf Beetle through control programs Manage high priority elm trees throughout the Shire by using one or more of the control methods outlined within the strategy. Where funds permit, medium priority trees will also be managed. Priority trees have been mapped and have been shown in Appendices 1 through to 6. Management of Elm Trees will occur yearly. Elm Leaf Beetle management techniques will be effective, safe and appropriate to limiting the effects of the beetle on elm trees within the Shire. Chemicals will be used in accordance with guidelines and public notification will be given prior to any works. Control programs in public areas will be managed accordingly, particularly in high use areas such as Caravan Parks. A separate program will be implemented for the Bright Caravan Park due to the high number of elm trees located within the park. Following consultation with leading experts, Council has decided that the preferred method of control is soil injection. This method, although a greater expense, provides superior protection for 2 years and has little impact on the tree. Stem injection methods are considered to be non-sustainable as holes need to be drilled into the tree periodically and foliage spraying poses risks to public safety and potential off target spraying of chemicals. The effectiveness of soil injection will however be monitored, as it is dependent on soil conditions and the uptake of the chemical into the tree. High priority trees will be soil injected every two years. Alpine Shire Council will be investing $40,000 annually for the management of priority elm trees. High priority trees will be managed initially, while medium and low priority trees can be considered for control methods between the two-year cycles.

Strategy 2 Removal of low quality elm trees In order to successfully control the Elm Leaf Beetle, the removal of low priority elm trees within the Shire is necessary. The removal program is to be implemented between June and August whilst elms have lost their leaves and are dormant. The trees, including all suckers, need to be cut off at ground level and poisoned to prevent regrowth.

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Removal programs will be undertaken progressively over a five-year period, with each stage being followed by a replacement/revegetation program. Alpine Shire Council will be investing $15,000 annually for tree removals.

Strategy 3 Support and facilitate public education Community education is vital throughout all steps of the Elm Leaf Beetle Management Strategy. Alpine Shire Council, along with the Alpine Elm Care Action Group, will provide support for the community and facilitate regular community meetings and updates to outline actions for the control of the beetle. Information on the Elm Leaf Beetle and control methods will be made readily available to the community. An excellent booklet, “Our Elms Need Friends” published by the Friends of the Elms is available at the Shire Offices and from each town Library. Council will make available its Environment Officer to facilitate this work.

Strategy 4 Monitoring, Evaluation and Reporting Annual reports will be used to determine the ongoing effectiveness of the program, using predetermined measures that reflect the impact of the Elm Leaf Beetle. The Elm Trees will be monitored between October and March to determine lifecycle stages and effectiveness of control programs. Tree health will also be monitored. Council will allocate staff and resources to undertake monitoring, evaluation and reporting.

Control Methods Foliage Spraying Spraying elm foliage when larvae or beetles are feeding on the leaves provides more immediate control. This method is to be used for high priority trees that are considered to have high social and aesthetic value. Foliage spraying is to occur between October and December annually. Trunk Banding Trunk banding is the simplest way of breaking the life cycle of the Elm Leaf Beetle. Trunk banding does not prevent re-infestation from untreated elms, therefore it works best where most elms in the area are treated. This method can kill significant

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numbers of larvae as they migrate down the tree trunk. Trunk banding can be achieved through a number of methods, including the use of chemicals or non-poisonous sticky-substances. Further information on trunk banding is available. Soil Injection Soil Injection has a greater expense, however can protect the tree for a number of years. The soil beneath the elm tree is injected with the insecticide. The tree absorbs the chemical into its vascular system and it ends up in the leaves, where it controls adult beetles and larvae. This technique is applied in spring when systematic insecticides are more readily transported throughout the canopy. Some trees may not be suited to soil injection as it depends on the area around the trunk. Trunk/Stem Injection This method of control can be used where the access to root zones is limited, or the use of canopy spray is not appropriate. The insecticide is delivered directly to the vascular system of the tree via a series of drill holes around the trunk. This method has similar results to soil injection however can damage the tree and leave it more susceptibly to disease if the drill holes are not sealed properly. This method can also be applied in environmentally sensitive areas. Biological Control Research into the introduction of a parasite for elm leaf beetle larvae began in 1991. In 1993 the Keith Turnbull Research Institute introduced a predatory wasp species for elm leaf beetle control. The wasp failed to establish here because the climate was too cold for them. Recently, a parasitic fly Erynniopsis antennata was released in Victoria. The fly is better suited to our climate so was expected to establish well. Once the parasitic fly is introduced to this area it is important to choose control measures that are compatible with bio-control, ie. measures that will not kill off the parasitic flies as well as the beetles. The most appropriate methods in this circumstance are soil or trunk injection (as the fly does not eat the leaves) and trunk banding. Pruning Trees Good pruning practices rarely remove more than ¼ to ⅓ of the crown, which in turn does not seriously interfere with the ability of the tree’s leafy crown to manufacture food. Lopping removes so much of the crown that it upsets an older tree’s well-developed crown-to-root ratio and temporarily cuts off its food-making ability (http://www.treexpert.com.au/pruning.html).

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Contacts Alpine Shire Council Cameron Alexander Environment Officer Ph (03) 57 550 555 Alpine Elm Care Action Group Roz Ferguson-Pelly Friends of the Elms Ph 0409 870 860

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