Mosaic Virus?

Am I crazy to think this is mosaic virus on a ficus? I’d say about 20 percent of the leaves are showing some sort of discoloration. There is also some leaf deformity. Plus, a fully rooted cutting I took from it has similar discoloration.

Any insight is appreciated. I am afraid it will spread to my other plants.

What do the undersides of the leaves look like?

I have an intermittent battle with spider mites on my microcarpas and they start out similar to your discoloration, complete with deformed growth, but mostly on the newer growth.

HallieReusch said:

Am I crazy to think this is mosaic virus on a ficus? I’d say about 20 percent of the leaves are showing some sort of discoloration. There is also some leaf deformity. Plus, a fully rooted cutting I took from it has similar discoloration.

Any insight is appreciated. I am afraid it will spread to my other plants.

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Given the symptoms, it makes sense to think that you are dealing with either a virus or a fungus.
In case it is a contagious disease, you could first isolate the tree to prevent spread while you identify the culprit, and then treat the tree for recovery. Think of it as bonsai social distance, especially if you have other ficus trees.
About the diesease, If the cutting came from the same infected parent plant, the disease (such as a virus) could have been there before the cutting was taken, and it may or may not be contagious to other trees in your garden.
If the cutting is from a different parent plant than the infected, then it is more likely that it is contagious to other ficus trees, and potentially to other tree species.

How healthy is this plant overall? It could very easily come from nutrient deficiencies.

Often people look for the worst that could happen, where these cases normally are very rare.

It's not a mosaic virus.
A mosaic virus would exhibit a very clear pattern around the veins, it's very distinct, it should have clear borders and usually expresses itself in younger foliage first.
The pictures show a blurry pattern, mottled, cloudy, whatever one wants to call it.

My experience with mosaic viruses is that most plants handle them pretty well and outgrow it with relative ease.
But it's not that.

Looks a bit like what happens when light levels change, indoor to outdoor move looking, when the indoor tissue gets hit with the outdoor sun.

Though the plant may have not moved, it is possible the changing sun angle is giving it different light.

I've had leaves like that before, but never lasting, at least not long enough to "figure it out".

A thorough pest check. Once for mites, once for scale.

Sorce

Not mosaic virus as stated above.

I’d say more likely nutrient deficiency.

So, in summary... yes, I am crazy to think this is mosaic virus. Okay, I guess I won't toss it.

@cbroad, the underside of the leaves has similar discoloration, but otherwise normal.

@leatherback, aside from what I mentioned in the original post, it seems healthy overall. It does take up water very slowly compared to my other figs, so I water and fertilize more infrequently. Given that, it might make sense that it is a nutrient deficiency.

@Wires_Guy_wires, Noted. I found this article which was making me second guess myself. Namely, this part: "In some leaves, the spots are more or less uniform size, small and densely scattered over the surface. In other cases, they are of various sizes, of indefinite outline, and appearing as irregular patches of light green, diffused widely throughout the blade of the leaf with no relation whatever to the position of the leaf veins." Probably a case of confirmation bias though.

Thanks all!

HallieReusch said:

the underside of the leaves has similar discoloration

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I'm still not convinced it's not spider mites, but I'm not really sure what else it could be...

cbroad said:

I'm still not convinced it's not spider mites, but I'm not really sure what else it could be...

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Oh, haha, I didn’t realize that’s what you meant when you asked if I looked under the leaves. I’m fairly confident it isn’t mites. I’m diligent about checking and treating for pests, yet this problem persists.

@HallieReusch
Here are a few pics of mine to compare to, I had sprayed a week ago and cleaned up the worst foliage. Pics are kind of hard to see but you can see the discoloration on mine and the deformed growth. My trees diagnosis was correct after putting a leaf under my microscope, although I could visibly see them crawling around. My problem went unnoticed until I saw the discoloration.

Found an older photo of my last battle with the mites. Here is the same plant back in March showing worse symptoms:

The ficus Hallie has is the type of ficus (benjamina?) that's used as an office plant all over Europe. If it would be susceptible to spider mites, I think it would've been an issue over here since the 1980's.

I'm not denying it could be spider mites, but it seems illogical since I know them as pretty resistant. We had one in our living room for 10 years and I don't remember it ever being in bad health. Still, could be spider mites though!

I'm thinking: what if it's a slight iron deficiency? The pattern checks out. A simple trace element solution containing Fe, as a spray or during watering, would do the trick almost immediately: two to four days and you'll see the result.

Wires_Guy_wires said:

If it would be susceptible to spider mites, I think it would've been an issue over here since the 1980's.

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I'm not understanding your logic. So there are no spider mites in Europe since 1980s?

Ficus probably aren't very susceptible to spider mites, but that has nothing to do with them harboring and being attacked by them. I had a benjamina right next to my microcarpa, and it got them too. So did my crapes that were right next to them, which aren't very susceptible to them either.

I raise orchids in addition to bonsai, and farm blueberries. Orchids have a list of at least 5 different viruses, blueberries have 9 viruses, of which only 7 have immunoassay developed for diagnosis. I rouge out a few blueberry bushes every year for viruses.

I'd say maybe on the viruses, I always treat for spider mites first. If foliage doesn't clean up, then I consider virus. Mosaic viruses in blueberries look something like your photos. I have seen at least 2 types of virus in the blueberry field. Though usually there's sunken areas on the surface of the leaf. Even if no necrotic spots show, the epidermis of the leaf will still have slightly sunken areas. I would especially consider virus if after you treated for mites, new leaves keep developing this blotching. And you have ruled out nutrition.

Virus is diagnosed by failure to make anything else fit. There are test kits for select virus, but they are are costly for the home grower. And, I know where to get kits for viruses that affect blueberries, I would have no idea where you would go for test kits for Ficus. California Ag Extension probably has information of viruses that affect culinary ficus. That would be where I would look for information on-line.

Generally virus are permanent. The only cure is to destroy the plant. There are a few viruses, that are specific for a different host plant that don't persist, but the majority are "forever", like herpes, chicken pox, and HIV in humans.

Some viruses are transmitted by insects with sucking or chewing mouth parts. THey chew or suck on an infected plant, then move to a clean plant, and their insect saliva leaks out while chewing on the uninfected plant, resulting in transfer of the virus. Keeping insect pests under control is critical to prevent virus from spreading in your collection. Nematodes can move virus from one tree in the ground to another. The most common virus vector in orchids are the cutting tools of the hobbyist. You must sterilize your cutting tools between trees, or between orchid plants if you are going to prevent the spread of virus. It has been documented that sap from infected blueberry bushes getting on the mechanical harvesters machines can infect all the bushes the harvester touches after it goes over the infected bush. Humans are the chief vector of viruses in many cases.

Dipping tools in 70% isopropyl alcohol then wiping the tool down with paper towel is fairly effective preventing virus transmission. Interestingly enough 90% isopropyl is less effective at removing virus. The alcohol wipe is a good habit to develop, and not as rough on the tools as 20% bleach solution or flaming the tool to kill virus.

So wipe your tools with alcohol after working on this suspect ficus. If the tree is not sentimental, I would destroy it rather than risk infection spreading beyond just the ficus.

I suspect many of our bonsai trees that are routinely propagated by cuttings are indeed virused, such as Serissa and others. Some tree species will simply be asymptomatic while carrying a virus. Isolating virus and identifying them is expensive. But in every economic crop where the money has been spent to search for viruses, Viruses have been found. I suspect, but don't know, that virus are fairly common in the houseplant or garden plant trade.

cbroad said:

I'm not understanding your logic. So there are no spider mites in Europe since 1980s?

Ficus probably aren't very susceptible to spider mites, but that has nothing to do with them harboring and being attacked by them. I had a benjamina right next to my microcarpa, and it got them too. So did my crapes that were right next to them, which aren't very susceptible to them either.

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No, spider mites are the most widespread indoor pest for plants in these colder parts of Europe. But I haven't seen them affect benjamina in the 29.97 years I've been alive. Not in offices, not in homes. Spider mites can jump hosts, but usually only if the 'easy' host is already overrun by them. That means there has to be a source somewhere. I'm mentioning the 1980's because that's when office plants became popular with the benjamina being the number 1 choice.

Viruses can be very specific and if they affect a certain plant, they either have to be aspecific (infect as many different species as possible) or they have to be transferred from a plant of the exact same species if they are specific. Those orchid viruses Leo is talking about, probably wouldn't affect pines for instance.
This factor is often overlooked. The tobacco industry are growing TMV-resistant plants, so transmission from cigarettes is rare nowadays although literature says it's the most common cause. Same goes for most cauliflowers, which are selected to be resistant to CMV.
If there are no ficuses growing in the wild, and most plant nurseries have a selection at the door on top of them treating for pests that act as a vector, how would a virus aimed at tropical plants end up on an indoor plant inside a home?

It has to be an aspecific virus, it has to find a host that eats ficus juice, the host need to spread to every part that's affected since these mosaic viruses rarely travel the sap stream. That's less likely than something like a deficiency or a lock out.

Wires_Guy_wires said:

. Spider mites can jump hosts, but usually only if the 'easy' host is already overrun by them

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That's all I was trying to get at. In my case it was because I introduced that microcarpa into the rest of my indoor garden last winter. I sprayed it with oil and had quarantined it for a week, but I was too anxious to get it under my 600w for recovery (it was a rehab project). A few of my other plants got mites, some that aren't normally affected.

I was trying to share with the OP my experiences because I saw something similar to my issues. Spider mites can be hard to spot until a lot of damage has been done, and at that point they can be hard to combat. I didn't want Hallie to have the same issues I had, and if they are mites, now is the best time to deal with them.

HallieReusch said:

So, in summary... yes, I am crazy to think this is mosaic virus. Okay, I guess I won't toss it.

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Many plant viruses can infect different plant species (including mosaic), and many are specific as @Wires_Guy_wires points out. There are thousands of viral "species", just as in animal systems. So it is not illogical to consider viral infection (not necessarily mosaic) as a potential issue in bonsai, and maybe in this case.

There can be other causes to the symptoms you see, such as nutrition or plant pathogens such as mites or aphids (keeping in mind that mites and aphids also do speed viruses).

Viruses in plants can spread within a leaf and do not need to infect all the plant, creating a patterns as you see in your pictures, in some but not all leaves.

If an infected vector (such as an insect, as @Leo in N E Illinois points out) forages on leaves of a species that can be used by the virus for replication, the infected cells are used for viral replication. Then, spread and infection of replicated viruses to nearby cells occurs via cell to cell channels, plasmodesmata, which are similar to gap junctions in animals, in terms that they allow the passage of molecules to surrounding cells.

Full plant infection does occur in viruses that can spread in the vascular system of an infected plant.

Another interesting aspect of the evolutionary history of plants and viruses is that plant specificity is also influenced by the vectors, the carriers of the viruses, which can be insect or in some cases pollen. If an insect has a specific plant host, or a set of plant species it uses for feeding or reproduction, It is also a logical evolutionary consequence for host pathogen interactions (plant-vector (insect)- pathogen(virus/fungus/bacteria/parasite) to develop.

I tend to see nutritional issues to affect many and not few leaves, in contrast to what you see, but @Wires_Guy_wires has observed a similar symptoms from nutritional deficiency, and @cbroad from mites, so you should see if that is the issue.

Some plant fungi can also use intracellular hyphae to spread via plasmodesmata.

You may not get the answer without sequencing or running some test such an Elisa. If you have the time an interest, here are some resources from UC Davies that don't need a lab to perform. https://anrcatalog.ucanr.edu/pdf/8002.pdf

Have you noticed any changes in the trees since the last picture?
I would try to correct easy to resolve issues such as nutrition, but would do it in quarantine, just to be on the safe side in case it is a pathogen. That is what I personally do with my trees.

@StarGazer
Thank you, that is a useful link there. Thank you.

Key I want to point out.

Good bonsai practice would be to routinely clean tools with 70% isopropyl alcohol between trees. Never cut one tree, and move to another, without wiping the tools down. This will go a long way to prevent the spread of viruses, and spread of bacterial infections, and to some degree slow down spread of fungal infections too.

Thanks, every one for the helpful insights.

I’m thinking I’ll isolate the tree and try to fix the problem before I toss it. It’s sort of ~sentimental~ since it came from my husband’s grandmother. I’ll be sad if I end up infecting all my trees, but I don’t have many. I’m early on in the hobby (read: obsession) and it’s a good lesson to learn. I can always buy more, right?!

Today, I trimmed off all visibly affected leaves and branches (pic below for reference) and hit it with a 16-16-16 fertilizer (which also contains Iron, @Wires_Guy_wires). I’ll keep ya’ll posted on how it goes!

Thanks to those of you who recommended 70% isopropyl alcohol for cleaning tools. I’ve been cleaning in between trees, but only with soap and hot water. I suppose that’s better than nothing, but it sounds like I really should be using alcohol as the cleaning agent.

Regarding the mites, you never know… so I’ll keep my eye out.

Thanks again!