Elm Leaf Beetle Treatment in Canberra

A leaf chewing beetle, Pyrrhalta luteola has had a devastating impact on most elm species in the Melbourne metropolitan area. Now they are found in Canberra. For five years the damage has been sporadic and minor but in the 2012-13 summer some trees received devastating damage.

The symptoms of infestation are:

• Chewing holes in the leaves in October
• Browning of the leaves that becomes more obvious from December through to April. A closer look at the leaves reveals that the surface has been chewed off.
• In heavy infestation the browning is followed by leaf drop. Severely infested trees are often removed after years of gradual decline unless early detection and treatment is implemented.

Treatment options:

Treatment via stem injection for elm leaf beetle is best done in November when the tree is in full leaf. This maximises the uptake of the chemical (imidacloprid) and minimises the damage done by the beetle. Treatment is also possible by soil injecting in early September so emerging leaves take up the chemical. It is important to note, whichever treatment option is chosen, there will still be chewing damage before the beetles die from ingesting the poison.

Elm leaf beetles are a particularly damaging pest because all stages (larvae, instars and beetles) feed on the leaves often with multiple generations in one year.

Other insect pests that turn leaves brown and dead looking are:

• Psyllids on Gum Tree Species: Red Gum (Eucalyptus blakelyi), Yellow Box (E. melliodora), Red Box (E. polyanthemos)
• Winter Bronzing Bug on Gum Trees (Eucalyptus sp.)
• Pear and Cherry Slug on Plum Trees, Cherry Trees, Hawthorn Trees and Pear Trees
• Sycamore Lace Bug on Plane Trees (Platanus sp.)
• Anthracnose (A fungal disease) on Plane trees Platanus sp.

We treat trees around the Canberra city and we service the broader Capital area including Queanbeyan, Goulburn, Bungendore, Yass, Harden, Young, Gunning, Gundaroo and Cootamundra. We have clients in these areas who engage us to help manage their trees on an ongoing basis.