HOW TO IDENTIFY THEM
The caterpillar of the white cedar moth (Leptocneria reducta) is about 4cm long and very hairy. They have a brown or black head and their body is mostly black with small brown or grey markings on them.
They are often seen climbing the outside walls of the house, around the windows and doors and over the brick work. Usually if there’s one on the wall, there will be many others as well as they are insects that mostly live in groups.
THE DAMAGE THEY CAUSE
These caterpillars adore Cape Lilac trees so if you have them in your garden or around your school, you can guarantee that somewhere nearby is a Cape Lilac with a line of caterpillars on its trunk.
White cedar moth caterpillars get around! At night, they head up the Cape Lilac tree and feed hungrily on the leaves, and sometimes there are so many of them that they strip the leaves completely. In the morning, they head down the trunk of the tree and find crevices and corners around the house, in the shed and even on the car to shelter. Then, in the evening they head back up the tree.
Apart from shredding the leaves of the Cape Lilac, these caterpillars are just ugly pests that will even get inside the house if they can. Once there, they will build sticky webs under furniture and when they die, they will have a horrible smell.
HOW TO CONTROL THEM
Of course, you can’t cut down the Cape Lilac tree even though it is their source of food. These trees are magnificent with their stunning purple flowers and cooling shade. And, it is probably impossible to spray all the caterpillars as more will just keep on coming until all the leaves of the tree are gone however, getting mum or dad to spray a surface spray around the windows or doors will help to stop them getting into the house.
Mudlarks and magpies don’t seem to like them which is a shame as they’re not much help in controlling their numbers and the White Cedar Moth Caterpillar doesn’t appear to have any other predators either.
The best way to deal with these hairy pests is to stop them from going up and down the tree. If they can’t get up the tree, they won’t have anything to eat and will die. To stop them from going up and down, ask mum or dad to wrap a rag that has been soaked in old car oil around the trunk of the tree. There are some chemicals available that can be used on the band around the trunk instead of the oil which your parents can ask about when they visit the local garden centre. The main thing is that the oil on the band means that the caterpillars just won’t be able to get up and down the tree and without food, they just can’t survive!