Ask-a-Dave's-Gardener: Pest Invasion, 2 by notagoodgardner

notagoodgardner wrote:
Hi guys, thanks for letting me visit your site. I live in Tambellup WA. My wife has a large garden in the middle of which is my small gum tree which I have raised from a seedling for a few years ago. That\'s about the limit of my gardening skills. The soil where it is growing in is composed of river sand, a layer of naturally occuring gravel and a clay base a few feet down. The tree is suffering from a pest(s) that is eating, laying eggs in and sucking the juices out of the leaves. The reason for this description is because they have caterpiller like bites out of them, they have markings like something is under the surface or has eaten them from the inside out (also tiny little white eggs on the surface) and the juvenile (?) leaves are shrivelling up when newly formed before they turn green. Hopefully I can attach some pictures.
When I first planted it it was strong and healthy. It\'s been a gradual process. I have been advised in the past to leave it to it\'s own devices because by the time you apply any treatment the bug will have moved on. This hasn\'t happened. It\'s now a about a meter high and losing the battle to survive. None of the other plants in our garden are suffering the same fate.
I do live in a realtively dry area and my little tree is planted just outside the rain shadow (?) of a fully grown gum tree which I\'m told can have an effect on it\'s growth.
Yes I am looking for a simple solution which doesn\'t look forthcoming from previous enquiries but perhaps a basic treatment and a suitable plant food to help it regain it\'s stength would be the solution. Just looking for some helpful advice please.