The leaves of the ornamental lime, not precisely a lime, more a limequot tree, had turned black. “It wasn’t like this the other day,” said Erik, who was immediately distressed by what looked like a celestial invasion.
The leaves were sticky to the touch and utterly covered in what looked like soot from an old steam train. “No stream trains around here though” Erik pondered.
Later he had a chance to discuss this with Khai on the phone. Khai was asking if there were ants in the tree. Yes, there were ants in the tree. He asked if there were tiny, disc-shaped and flattish insects, almost the colour of the leaves. There were. So Khai told Erik the story of the ant and the scale insect.
The scale insect is blind and it cant move by itself. The ant is opportunistic and loves indenturing slaves to get what it wants when it can’t do something itself. So the ant carries the scale insect up the tree and places it in position on a leaf where it will stay. The ant literally piggybacks it up there winding its way through the branches.
The scale insects lodge their suckers into the leaf where are going to stay and start extracting. A sticky residue starts to cover the whole leaf. And that is what the ant wants. That is why it hovers around and protects the scale insect after it has placed it there. Not that the scale needs protecting. It has a hard shell. It is almost invisible, and it is virtually impossible to remove or assassinate (without toxic chemicals).
Skip to microscope view – where we see the tiny scale insect up 400% on the laptop screen and its heart is beating.
The sticky residue produced by the scale insect attracts a black mould from the atmosphere. The mould is like soot on an old train, but it merely comes from the air. There are no trains around here. It blackens the leaves, and the ants leave it behind when they carry the sticky residue away.
The blackness stops the trees receiving sunlight and all the leaves wither. Suddenly with an infestation of these little creatures working in unison, there is a dying tree. Just last week it was a fantastic vibrant, healthy deep green with flowers and fruit.
Khai’s remedy is soap and water for the ants, twice – the whole tree and surrounds. Such a treatment will stop the ants in their tracks, but it needs to be dishwashing liquid, not bathroom soap. Once these are gone, we need a remedy for the scale.
It so happens that the organic pesticide BBQ distillation that we can get locally for orchids works. We have actually found a solution to scale. One application and a week later, the leaves are clean, and there are no scale insects left at all.