Q: How do you get rid of borers in a mock orange hedge? Donna – Wavell Heights
A: Borers are the larvae (caterpillar like things) of several different types of insects.
They bore through branches and trunks of trees and plants and feed on the plant’s life giving cells formed by the phloem and cambiums layers. Being hidden away within the structure of the plant they are very difficult to control.
The best method of control would be to use a ‘systemic’ insecticide. This means that the active ingredient in the insecticide is absorbed by the plant into its internal systems, and is spread throughout the plant, thereby affecting insects feeding on the plant (depending on the type of insect).
Try spraying with either Rogor or Confidor. Give your plant a really good covering of the spray, both on the upper AND lower surfaces of the leaves. Let the insecticide drip down the stems and branches as well, so that some of it hopefully gets into the borer holes.
The borer holes are, more often than not, covered with dust or resin, and the insecticide may not get in. Repeat the spray three to four weeks later. This will more than likely fix your problem.
AN ‘ASIDE’. Something interesting with the borer type insects is that they somehow detect plants which are weak and stressed. It often happens that just one within a group of plants of the same species is attacked, and that one plant will be the weakest in that group.
Maybe nature’s way of culling and getting rid of the weak! Her principle of ‘Survival of the fittest’.
What this could point to is that possibly your Mock Orange (Murraya paniculata) has other problems that you need to look into – particularly watering, soil depth and health, and fertility.
