Foliar Nematodes: How to eliminate the infection in a bonsai ficus tree

Asked September 17, 2020, 9:54 PM EDT

I think that Foliar Nematodes have infected the coleus plant next to my bonsai (see pictures), and the canna lily I have (see picture). I noticed the steams of the coleus have become very weak and can no longer support the weight of the plant. I saw small translucent worms wiggling their way in and out of a lesion in the stem. I used the same watering can to water my plants, and the rose of the can touched the leaves of each of the plants. I'm now worried that I might have introduced the parasite to my bonsai. I'm wondering how I can eliminate the parasite and prevent them from taking hold. I have isolated my bonsai tree and have removed all leaves that look even remotely diseased. The bonsai was a special gift that my brother gave me. I'm committed to doing whatever it takes to keep the tree alive and squash the infection. Thank you for any help or suggestions you might be able to give me regarding this.

Multnomah County Oregon

1 Response

It sounds as if the coleus may have been kept too wet. That would cause a weak stem which is subject to invasion by small clear worms.

The good news is that nematodes are too small to see without magnification. Further, I don't see any of the tell-tale symptoms of foliar nematodes.

Then, too, if foliar nematodes were present, the only helpful treatment would be to discard the entire plant.

The all-green has leaf lesions due to mechanical damage such as rubbing or folding; and a water imbalance, most likely due to an uneven supply.