I own and operate a small bamboo nursery in British Columbia, Canada which lies just north of Washington State. I purchase a fair amount of my stock in Washington and IÂm afraid that I may have accidentally imported a very aggressive mite along with one of my bamboo shipments.
Two years ago, there were only a few leaves that showed signs of mite damage and at that time I thought that it was caused by some naturally occurring mite that exists in every outdoor garden. In 2008 my bamboo nursery experienced a population explosion of this pest and the result has been significant infestation of many of my bamboo plants. The mite has an affinity for most Phyllostachys species (Nigra, Henon, Megurochiku, etc.) it has not bothered my Fargesia, Borinda or Pleioblastus however. The leaf damage is significant and has resulted in unsightly leaves as well as stressed my bamboo to the point that they did not grow much last year at all.
Strategies I have tried to control the mite infestation:
1) I have removed and burned the infected leaves from each bamboo plant.
2) I have tried using insecticidal soap on the underside of the leaves but due to the number and size of my bamboo plants this isnÂt a realistic option.
3) I have imported predatory mites to eat the problematic mites but this was not even remotely successful.
I have purchased two insecticides that contain "Imidacloprid": Green Light Tree & Shrub Systemic Insect Killer Â Imidacloprid 1.47% and Bayer Advanced Complete Insect Killer Â Imidacloprid .72%. A bamboo nursery told me that the use of one or both of these products will be drawn into the plant tissue and when the mite begins to suck the juices from the leaves, they will ingest the insecticide and die. This will supposedly produce a systemic wide defense from these mites and should last the entire year.
The problem with these insecticides is that the dosage listed on the label is rated as if you are spraying this product on a lawn or garden area where the plant is rooted in the ground. My bamboo are all in pots so IÂm not sure if I should use the same dosage, more or less. I tried a little of this product in the fall of 2008 but didnÂt notice any difference in my plants Â maybe it takes more time.
In summary I have a nasty problem and I could really use some good advice on how to eliminate this mite. If you have any comments I may find useful please forward them to me if you have time or point me in the direction (website, email, etc.) where I may find some assistance.
Thank you very much.