Nick I have a Portia coerulea, isolated in a corner( under the notion that most Portia's are virused)- it has not showed signs of virus in the leaves. Waiting for it to bloom. I don't mix it with other plants, but again I grow outside, and so I don't have to worry about close proximity. If I get a virus kit, I will certainly test it out.

I have kept two plants which I really like, and know to have ORSV. All other positive-virus plants have been long tossed. These two are away from the other plants and I have big red tags in their pots to remind me. A third plant, tested fairly recently, always blooms in Oct so I will let it have its final flowers before tossing; the plant has never shown any sign of virus but tests positive.

I have plants that I know are virused but, they are the plants whith the greatest sentimental value for me. They acctually seem to be my most resiliant plants. As long as they are growing and blooming for me I'll keep them. The biggest drawback is that I know keeping them in my collection puts me right out of any orchid trading wich I think would be a lot of fun. But, I could never send anyone one of my plants without first segregating and testing it for viruses. I hope to test them all eventually but it is one of those 'someday' projects that haS not yet been worth the expense.

Meg

I think the real trick is to have the plants well saturated with a systemic insecticide so no aphids or other bugs can suck juices and then fly to other plants. One probably needs to do more of this with all the plants, as no doubt a number of our 'healthy' plants are virused and have not shown signs of it yet. I'm using more of this Bayer Advantage which would be great if it works as well as people say it does as it is easy to apply without having to gear up in bio-hazard suits like I used to do for the likes of Cygon. I still have some Cygon around, it has been pulled off the market but I'll use it, problem is it is so toxic one really has to suit up.

Right now aphids are not too prevalent, I plant to soak everything in Bayer Advantage and then see if the Aphids stay away next spring.

Nick

It seems like using systemic insecticides on a virused plant may not guarantee that bugs can't spread the virus, since systemics don't kill immediately. Admittedly aphids don't move around much, but if one did go to another plant before it died, couldn't it carry the virus?

Nick, If you choose to use an Imidacloprid product, I suggest that you use a strategy of multiple exposures. This is the recommended route. One exposure kills the immediate problem. Multiple exposures are expected to provide systemic protection for long-term effect.

--Stitz--

Do you know the interval which is optimum?

Nick

Nick

I have never seen any studies that show how the virus can be transmitted to different orchid genera. Using contaminated tools is obvious, but much of the other information is purely anecdotal and much of it is from individuals who have never even tested their plants for virus. Without this information, you cannot have 100% confdence in your countermeasures.

Your focus on insect control may be wasted time. Insects might not even be a source of infection. It may be that some genera are easily infected by splashed water. Maybe it is as easy as touching an infected plant and getting the sap on your hands and then touching another plant. Do you wear disposable gloves when you handle the virused plants? The point is that if you keep virused plants, you are assuming an unknown risk.

Mike

Agree with a lot you say. I don't keep virused plants with my collection. My daughter lives 20 miles away, she has one, my neighbor who has the 2 Cymbidiums is a long block away. I would not have a virused plant on my property. It's been over a year since I found one but when and if, they leave the same day.

Nick

Two guys who've been in orchids for 30+ & 35+ years have had virused plants in their large collections for as long as 20 years. They keep these plants somewhat separate from the others, but all their plants are in their greenhouses. They take the usual precautions when handling.

I have no idea if this is feasible or if they've had consequences they don't mention.

Also, have there been threads here about orchids' "immune systems"? I could have imagined this, but were people saying that orchids carry the potential for virus, just as people carry dormant germs in their bodies?

Only if the plant or person undergoes significant stress does the immune system weaken and a virus or disease may develop. Or if someone uses bad practices when handling the orchid.

Is the theory out there? A product of my quirky brain?

Whitecat8

I do not believe plants have immune systems like the ones we have. That said, they must have some form of resistance to bacterial and fungal attack or they wouldn't be around. It is conceivable that stress may permit the virus to run rampant in the plant. Maybe the virus is the source of stress in the plant causing it to fall victim to other ills. It is also conceivable that there is variation in individual resistance to virus. The problem is that all of this is conjecture as is most of the information that you read here and elsewhere on the web.

All I know for sure is that the virus in infected phals can infect other phals and that some of them die as a result. I thought I was always careful, but it happened anyway.

Mike

I have no doubt that orchids, like all living things, have a defense mechanism against outside dangers. In us we call it the immune system. They undoubtably have something similar.

I have been told that stressed plants exhibited the virus which then subsequently seemed to disappear. Or physical evidence there of, not the chemical test. My plant is a good example. At one time evidence of virus, now no evidence of virus. Could be nothing else other than stress, a couple of years ago, allowing the virus to show itself and now is dormant again.

What this illustrates is that there may be many more virused plants in all of our collections which, if in excellent health otherwise, will not show any signs of it. If one would test every plant in a large collection, there would be a significant number which would test positive.

Nick