neem oil, aphids and CMV

[scout]

I have what looks like CMV on my dendrobium. I looked in Cynthia's photo gallery, and the little black spots on my den look very much like one of the photos. I continued to read in the previous thread, "Viruses and Infections" and saw a post where Cynthia mentions aphids as a transmitter of illness and neem oil as good control. My questions are 1) are aphids the little buggers flying all over the decaying moss in my - cannot be repotted because it's in bloom - phal ? If yes, 2) how do I apply the neem oil? And 3) covering my bases in case it's not a virus, I wiped the leaves with peroxide and then sprayed a homemade brew of cinnamon and rubbing alcohol over the leaves -- nothing's dead yet, but I see new black spots on the my cattleya and am thinking maybe I should use something stronger. What do you think my next steps ought to be? Thank you.

[mayres]

Very rarely will you see aphids flying - once they have arrived they tend to stay semi-put though I'm sure they do slowly walk from place to place. Most likely "little buggers" flying around your decaying moss are fungus gnats, which I do not believe are injurious to your plant(s) - just annoying. If you are going to try to and stay with the natural methods you will need to be very diligent as they methods are not as thorough as some other stronger methods (assuming that pests of one form or another or actually the issue). Personally I have found Bayer or Ortho Rose and Flower systemic in a ready to use spray bottle effective - and lasts for up to 30 days. Do you have lots of good air circulation? This can be important in preventing disease as well. Good luck - mike

[Cynthia, Prescott, AZ]

I think 99 times out of a hundred, black spots are fungal. Are you letting the plants get too cold for their type? Or are you spraying/misting/watering late in the day so that the leaves are not dry when the temp starts to fall? Spores are pretty much everywhere, so good culture is the best preventative. Spots themselves are usually hard to use for judging virus infection, unless the spots are really stripes and run along the veins of the tissue. And even then, it is sometimes fungal due to mechanical damage, such as when the bulbs have shrivaled and then refilled, causing a breach in the tissue along the shrivel lines and fungus enters this line of damage. More often I have a sense of some problem with the plant because it grows poorly compared to how it should, but in the end, I will be testing everything, because quite often there is no indication at all that a plant is virused. For a casual home grower, this kind of attention to virus is probably not needed, as long as proper techniques are always used, like sterilizing tools before cutting into a plant, and washing hands before repotting, and disposable gloves for this job is a good idea. In my case, I already know I have a high incidence of virus, so a good cleanup is inorder.

Aphids are the little green (usually) bugs that are generally seen clustering around rose buds, for those that garden a lot. They have wings, but they are rarely seen flying, at least I haven't ever seen them fly. Look up aphid on Google to see what they look like. The tiny black flys that seem to lazily and randomly move around anything that attracts them are fugus gnats, and from recent forums I've read, their larvae is thread like. Neem oil may be useful for gnats if the mix is drenched with it, but there are other things that might work better, try google on 'fungus gnats'.

When you need neem as a pesticide for aphids, mites, and scale, you would want to thoroughly spray all surfaces of your plants and then keep them out of bright light and very warm conditions for a couple of days. A repeat spraying a week or two later might also be a good idea.

[scout]

First the bugs, they are not green and they do fly; ergo, they seem to be, as both Mike and Cynthia suggested, fungus gnats. I have been only diligentish with my natural methods, I tend to err on the less is more scale of ways to muck things up, but I am tempted by Mike's suggestion of Ortho Rose and Flower systemic, because it seems more of a sure bet than my kitchen concoctions. And while the gnats are not hurting things, I have to admit I really hate seeing them floating all around my orchids.

Secondly, I am oddly disappointed to hear that my random spotting is less likely a virus and more typical of fungus. I was so proud to have done a bit of research and made my diagnosis. Better luck next time. So then, why the fungus? I water early in the day and the plants seem to have good air circulation, but I live in San Francisco, and our summers are notoriously cold, so I suspect that may in fact, as Cynthia mentions, be the source of the trouble. How to warm them up is a real dilemma, as I don't have the space for lights and what not, but I'll keep thinking about it, and maybe a solution will present itself. Or maybe the sun will shine here. Or maybe pigs will fly.

Thank you Mike and Cynthia for you kind responses to my questions.

Best,
Elizabeth

[latsyrc]

Actually, fungus gnats do harm plants--their larvae chomp on roots, which is not fun for the plant and can allow diseases in. Fungus gnats that linger around your plant frequently mean the media is too wet. Combined with the fungus itself, I'd guess a little more drying out is in order.

[Cynthia, Prescott, AZ]

Check out the thread on 'Mold'. There maybe some ideas there for gnats. I am not sure the systemic will kill all the larvae, but maybe the problem with most of these pesticides is that the adult gnats are still flying when you kill off the larvae and will shortly thereafter lay somemore eggs. So no doubt repeat doses of what ever you use will probably be needed. Cynthia