I have 2 Orange trees that were damaged by the cold last winter. They bloomed twice and each time the temps dropped and so did the blooms. Both trees have had a difficult time recovering and their leaf production has been minimal. A few weeks ago I began noticing notched out leaf edges and curled leaves. The culprit has been identified as a Citrus Root Weevil and unfortunately they are very hard to eradicate and to do so their life cycle has to be interrupted. The orange trees serve as a shade structure for a few of my chids and today I was mortified to see that the weevils have been dining on my fully developed dendrobium buds.
One bud was completely gone and another two had been drilled and gutted. I moved the plant to a safer location but the damage has already been done.
I don't know if I'll be able to get rid of these wicked insects. Today I removed all my Chids from the trees and gave the citrus leaves, trunks, and ground beneath a thorough spraying with Orthene Systemic Pesticide. This is not considered to be an effective treatment and from what I've read there is no tried and true method for killing these bugs.
Systemics are never recommended for fruit bearing trees but these trees did not set fruit this season. I'm planning on treating the entire yard with diatomaceous earth and will continue to spray the tree and area beneath with systemics and neem oil every week. I'm hoping the DE will kill the larval stages as they emerge from the ground. I don't like to use pesticides but if something isn't done the trees will perish. I need to find an effective pesticide that will penetrate the soil beneath the trees to kill the immature bugs that feed on the roots. If anyone has suggestions feel free to chime in.