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8 Common Orchid Viruses (Here’s How to Deal with Them)

Many owners of exotic plant collections consider viral diseases of orchids to be a death sentence for the flower: treatment is impossible, and the only option is to discard them.

Is this true, and is there any hope of saving these exotic beauties?

Very few orchid diseases are caused by viruses. Spots on the leaves that resemble stripes or circles and the presence of spots on the leaves themselves are both symptoms of the disease. Orchids of Phalaenopsis, Vanda, and Cymbidium are susceptible to viral diseases.

Modern orchid experts have identified more than 50 orchid-specific viruses.

Some of them affect many orchid species, while others only affect flowers of a single genus.

In addition, they show up in different ways. For example, even the same virus looks different on the leaves of various plants with different leaf plate textures.

Actual Signs of Viral Infection In Orchids

A few universal signs point to a viral infection in the orchid.

First, the stripes on the petals, which can be white, pinkish, or dark, or the ridges or notches, stand out against the plant’s weak growth and sad state.

Suppose young leaves develop visible yellowish patterns such as spots, strokes, and various geometric figures such as rings, ovals, and rhombuses.

In that case, there is every reason to suspect that the orchid is infected with a virus.

As you look more closely, the pattern changes color. First, it turns black or reddish-brown, and then it becomes dark brown and slightly raised.

Ways That A Virus Can Get Into A Houseplant

The virus spreads from a diseased orchid to a healthy one via the sap of an infected plant.

It is often spread by sucking pests like aphids, mites, and others.

When insects like these appear, you should always take action to eliminate them.

Infection also enters the house via a recently purchased orchid.

Many orchid growers with extensive plant collections say this is especially common with flowers from Dutch suppliers.

This is why experts always insist on mandatory quarantine and thorough cleaning of tools after working with transplants and dividing rhizomes.

Other orchids in the home collection become infected due to the grower’s negligence.

After getting sap on your hands, wash them with soap and water or disinfect or throw away the rubber gloves you used to move the plants.

Can Viral Diseases In Orchids Be Cured?

Most experts believe it is best to destroy infected plants as soon as possible so that the virus does not spread.

In some cases, a leaf showing signs of viral infection was immediately cut off, diagnosed, and destroyed, and the plant usually grew for 5-7 years without showing the disease.

However, there appears to be no effective cure for viral infection in exotic plants at this time; growers have the freedom to choose what to do with their orchids.

The Most Common Species of Orchid Viruses

Not more than 20 species of viruses that are known to affect indoor orchids are common in temperate climates. However, the following ones are more likely to hurt plants:

Orchid fleck virus (OFV)

Orchid fleck virus (OFV) can be found on different orchids. It is incredibly sneaky because it shows up in different ways.

When this virus infects cymbidium leaf plates, the surface is rarely covered with rings. Instead, 

bands made of small squares or rectangles are more likely to be seen. Their color can change quickly, within three weeks, slowly, over several months or even a year, to become darker.

On the dendrobium’s leaves, they look like rings, double rhombuses, or ovals.

The virus can be mistaken for a fungal infection because the affected tissues do not show signs of stress for a long time.

However, keep in mind that viral spots will not grow fungal spores. The infection in Phalaenopsis is even more subtle.

The orchid can carry the virus for a long time without showing any symptoms, or the usual spots only show up on the old lower leaf plates and not on the young ones on top.

Fungus diseases tend to spread much faster through the flower.

Treatment for this viral disease is nearly impossible, and the plants are usually discarded.

It is rare for the virus to only act when certain things happen, like when the temperature is 26 degrees or higher or when the humidity is more than 80%.

Therefore, it doesn’t make sense to leave it and risk the safety of the entire collection.

After all, you’ll need to keep a close eye on it, water it separately from the rest of your plants, and disinfect any tools you use for transplanting.

Dendrobium mosaic virus (DeMV)

Dendrobium mosaic virus (DeMV) – is known as Dendrobium mosaic virus.

From the outside, it looks almost the same as the last species. The leaves have the same double rhombuses, ring-shaped divisions, or ovals.

But it seems to affect more natural species than hybrids. Unfortunately, there is no cure for the diseased plant, so it must be destroyed.

Leave an infected orchid alone only in rare cases where the virus is not active under certain conditions and the plant is kept away from other house plants.

Tobacco Mosaic Virus (TMV)

Tobacco Mosaic Virus (TMV) doesn’t usually affect indoor orchids; when it does, it’s generally with another virus. It rarely happens on its own.

Not only do the leaves of a cattleya look bad, but so do the petals. The central vein of the young sprout is usually visible, with light streaks running through it.

When it blooms, the leaf has yellow-reddish-brown spots and looks rotten.

In addition, the leaves that are opening up are so papery and misshapen that they can’t even open properly, which makes them look very miserable.

On the other hand, cymbidium leaf infestations can take on the appearance of recessed, blackened circles similar to cattleya infestations with time.

On the leaves of an infected oncidium, the pattern looks like light rings and circular parts that get darker and more slightly raised.

This virus can only be identified in a laboratory. It is impossible to treat orchids infected with viral disease because the infection is ferocious.

It can be dormant for a short time, but once it starts to grow, there is no way to save the plant.

Odontoglossum Ringpot Virus (ORSV)

Odontoglossum ringspot virus (ORSV), or Odontoglossum ringspot virus – the infection of different orchid species is multifaceted and depends on the texture of the leaves.

Sometimes only the outer rim of the ring turns brown, leaving the center green. This is common on thin leaves with double rings that darken over time.

Leaf plates of Phalaenopsis, Paphiopedilum, Dendrobium, and Cymbidium rarely have ring-shaped patterns.

Instead, a series of faint lines and strokes are formed and joined to form irregular rhombuses.

Phalaenopsis Chlorosis Spot Virus (PhCSV)

Phalaenopsis chlorosis spot virus (PhCSV) is one of the most recent discoveries by Taiwanese researchers. 

It was discovered in 2004 but wasn’t known for a few years because it looked like other viral infections.

An accurate diagnosis of this infection is only possible in specialized laboratories.

There have been no other reports of its presence outside the Phalaenopsis, Cattleya, and Dendrobium genera. 

It looks like chlorosis because it stops chlorophyll from forming in the plant’s tissue cells, which stops photosynthesis. 

Initially appearing as pink or yellow spots on the leaves, it gradually pushes in and becomes light, nearly white color on the undersides.

Since so little is known about the virus, it’s impossible to say for sure whether or not it can be eradicated. 

However, there is a chance to save the orchid if the infestation spreads slowly and appears only on one leaf. 

Cut off the infected leaf with a disinfected knife and place it in a separate room. 

The cut should be cinnamon-treated, and the cut leaf should be discarded. If new signs of the virus are found on other leaves, you must get rid of the plant.

Turnip Mosaic Virus (TuMV)

Turnip mosaic virus (TuMV) is a rare viral infection that looks like small bloated balls. It has only been seen on Phalaenopsis so far.

Experts say to get rid of diseased orchids because they haven’t been studied enough, but there have been times when a flower kept away from other plants grew usually for a long time as long as the conditions for keeping it didn’t change.

Calanthe Mild Mosaic Potyvirus (CalMMV)

Calanthe mild mosaic potyvirus (CalMMV) is another newly discovered and understudied viral infection in Japan.

Still pretty rare in temperate regions, it gets into homes with Asian orchids and has only been seen on calanthe and phalaenopsis so far.

It looks like a mosaic of light-colored stripes and pieces of lines that get darker over time.

This virus causes a change in petal coloration in plants. The damaged flowers can’t be fixed, so they must be thrown away.

Capsicum Chlorosis Virus

CaCV (Capsicum chlorosis virus) is a virus that is also known as Taiwan-Virus.

It is easily identified by its double ring-shaped spots, small rings inside larger ones. At times, the pattern looks like a smoky cloud.

The disease hasn’t been studied well either, so no one knows if it can be cured completely.

Many cases of early-stage lesions being removed and the infection not showing up for 5 or 7 years.

Other viruses rarely found on orchids include the Tomato Spotted Wilt Virus TSWV and Carnation Mottle Virus (CarMV).

How To Tell The Difference Between A Virus And Other Diseases?

In some ways, viral lesions resemble fungal infections, parasitic infestations, and, to a lesser extent, bacterial infections.

Practically, it’s nearly impossible to separate all the different types of diseases. However, the progression of the spots over time may be of some assistance.

  • Fungal lesions appear immediately with dark streaks on which fungal spores later appear, whereas viral infections first appear light and then darken in appearance.
  • In contrast to a virus infection, which takes time to manifest itself, pest infestations manifest as light, sunken lesions.
  • The spots on a bacterial lesion tend to grow by the hour, which is very different from how viral diseases work.

The only place where you can be sure of the viral lesion and the type of virus is in a lab.

Conclusion

Scientists are still searching for effective ways to combat viral diseases that commonly kill orchids when they are indoors. Therefore, it is not possible to completely cure the plants.

In such conditions, it is only possible to keep beloved plants that are pathetic to throw away for a short time when the viral infection does not manifest itself and is inactive.

This, however, is always accompanied by difficulties. First, the virus-carrying flower must be isolated and carefully monitored to avoid infecting the entire collection.

You have to decide if it’s worth putting all your plants at risk for one sick orchid, even if it’s your favorite.