December 02, 2020 / by Danny Mavis

Trees are a stunning part of Earth. From the first buds of spring to the colourful leaves in the fall, they are simply gorgeous. On top of being a beautiful addition to any landscape, trees can also bring many benefits to your property such as creating shade to protect your landscape from the scorching sun and keeping your home cooler.

If you’re wondering which trees you should plant, Elm trees are an interesting option to consider. They can be an asset to any landscape and can provide you with cooling shade and unrivalled beauty for many years to come. Elms are also resistant to winds, various other adverse conditions and tolerant to atmospheric pollution. This explains why they are some of the most commonly planted shade trees in the country.

However, there is one thing that can trigger the health and beauty of these trees – the elm tree bug killer. It is responsible for a great part of the damages in Elm trees all over Australia. This bug is destructive and eats into leaves, which can cause a decrease in the trees’ ability to photosynthesize light into energy creating food. This results in stress and decline as energy reserves dwindle and may lead to the eventual death of the tree. The good news is, leaf beetle infestation is treatable.

elm tree in the park

How to Treat Elm Leaf Beetle

The best way to address this problem will depend on the season, the degree of insect infestation, the tree’s size and its location. Currently, the most effective control measure for infestation is a chemical application. Pesticides can be used while the bugs are still quite young. Considering the fact that handling chemicals involves certain dangers, it would be wise to hire a company that performs an elm tree bug killer treatment to apply the product. Contact several companies to obtain estimates, then hire the one you like best to spray the tree at the appropriate time.

Early treatment is essential. Trunk injection with Imidacloprid is one of the most effective and environmentally-friendly options. The chemical is injected directly into the trunk of the tree, which will then transport the chemical to the leaves where it kills the beetles. The bugs only need to ingest a small amount of leaf material for the chemical to kill them. For younger trees, foliar sprays may be enough to address the problem, but this may not be sufficient for older trees due to the size of large elm trees. It should be applied twice a year for best results.

elm leaf beetle treatment

You can also try non-chemical control banding. Sometimes this works to trap larvae that migrate down the trunk. Adhesive tape can also be wrapped around the trunk in a strip about 20cm wide, with the sticky side facing out. This can help break the Elm Leaf beetle lifecycle. However, the bands need to be applied before the larvae start to crawl down the trunk. Keep in mind that banding treatments may need to be replaced several times in a season if beetle numbers are high. While this method will not reduce damage in the year of application, it should reduce beetle numbers and damage in subsequent years.

Although some people use soil injections for Elm Leaf beetle control, experts don’t recommend this method. Soil injection involves injecting the soil under the tree and can be applied to trees of any diameter. With this method, the chemical is taken by the feeder roots and transported through the tree’s vascular system to the shoots and leaves where it kills the adult beetle and larvae. Because the movement of the chemical is slow, the injections need to be carried out around 6-8 weeks prior to the beetles emerging from hibernation. Keep in mind that soil injection is detrimental to soil flora and fauna, including earthworms and mycorrhizal. Applications near rivers and creeks or near food gardens can pose particular risks for human health as it will kill all nutrients in the soil.

tree care trunk injections

How Often Should Be a Tree Treated for Elm Leaf Beetle

Experts suggest chemical treatment every three years, but in some instances, the treatment will last longer, particularly if your trees are isolated from other trees with an Elm Beetle infestation. In the third year, you may start to see a small increase in damage, which is normally at manageable, acceptable levels. However, if left much longer, the Elm Beetle population may increase dramatically. To reduce chemical use, you can try trunk banding in the third and even the fourth year.

But what if your neighbour has Elm Leaf Beetle and doesn’t treat his tree? Although neighbouring trees can see some crossover of flying Elm Leaf beetles, if your tree is properly treated, it will still look very good even if your neighbour doesn’t treat their tree. Generally, it’s the Elm beetle larvae that do the most significant damage and they neither fly nor hitchhike.