Early season symptom's (August to November appear as shot holes in leaves and skeletonisation and discoloration of foliage occurs at the peak of infestation (December to February). Severely damaged trees may be completely defoliated. Consecutive years of defoliation an cause limb dieback and may lead to whole tree decline.
While Elm Leaf Beetle will never be eradicated but it can be managed - there is no reason for any Elm tree to be lost to an Elm Leaf Beetle outbreak. Early prevention is necessary and there is only a small window of opportunity for its effective treatment.Current methods of control include soil injection, canopy spraying, trunk injection, bark banding and biological control (the use of predator insects). Soil injection is perhaps the easiest, safest and most effective control treatment at present and remains persistent in the tree for up to two years. This involves the application of the chemical Confidorâ or Merit® to the root zone of the tree. Confidorâ or Merit® is a systemic, non-residual insecticide that is safe to use as it remains within the treated tee. It is passed from the roots to leaves of a tree in a process known as trans-location and poisons the feeding beetles as they ingest the leaf tissue.
Timing of Control
Elm tree owners should act now for August to October is the only time of the year that Elms can be treated.All large, old or otherwise valuable trees should be treated with soil injection. Maintaining stress free trees all year round is also important and will reduce the severity of infestations. Dead or dying limbs and suckers should be removed and trees should be kept well watered over the warmer months.Elm tree owners should have an arborist inspect their trees if they are in doubt as to how to maintain their health and structure.If we are to retain our valuable Elms in both the short and long term, we must stop this opportunistic pest and its cycle of devastation in its tracks. Is your Elm tree vulnerable? Email firstname.lastname@example.org to arrange an inspection of your elm tree.