Dendrobium phal with speckled silvery sticky underleaf

[metazooa]

What is wrong with my dendrobium?

[Dollythehun]

You have a severe case of spider mites. Mite X or Bayer 3 in 1 systemic spray with imidacloprid. Wash the plant well and spray...others will chime in with more organic solutions...dish soap and alcohol solutions, need oil etc. I would take it outside and use a chemical first round.

[rbarata]

Probably it is infested with spider mites. Rub a cotton embedded in alcohol on the underside of the leaves. If you find a red tinge on it, it's mites.

[metazooa]

unpotted the plant and disposed of the medium. I washed the plant with water which got rid of the speckles (Which im guessing are clumps of mites) And then I sprayed every inch of the plant with insecticidal soap containing pyrethrin and sulfur. lets see how this goes.

[rbarata]

Good luck!

PS-Today I've found one of my plants also infested so, good luck to me also!

[jcec1]

Tbh, this plant is so severely infested that if it was mine I would trash it. I would worry about it infesting other plants, because there will be an abundance of eggs you will get further generations. If you want to keep it, I would keep it in another room with no other plants, mites are so small that they will be carried on air currents and spread easily. Also, I would spray any other plants that you have as they may also be harbouring mites.

[Roberta]

It is also important to spray repeatedly, since each treatment typically kills the adults, but not eggs. So you have to hit it about every 5 days for at least three weeks, more would be safe. Also remember that mites are not insects, but rather arachnids. So you need a miticide, not an insecticide. The pyrethrin should help, and soap/alcohol treatment will kill the ones that it hits... but be sure that any pesticides that are used are rated as effective against mites.

[Ray]

Low humidity favors mites, so once you have eliminated the infestation, raising the RH can reduce the likelihood of them returning.

[estación seca]

Welcome to the Orchid Board!

The above is good advice. I use insecticidal soap or a 70% alcohol solution spray, neither of which kills eggs.

Permethrins are used on household animals as tick killers. They do have activity against mites. However, mites quickly become resistant to pesticides.

You will learn which orchids are more susceptible. Most of those with thin leaves are, such as this kind of Dendrobium. Others very susceptible include Cymbidium, Miltonia and Miltoniopsis, Oncidium and Phalaenopsis.

[metazooa]

Update: I've switched over to 70% isopropyl alcohol spray every 5 days, and the spider mites seem to be gone I even cut off a portion of the leaf to look at it under a microscope and there were no spider mites on it. I will continue spraying it with the alcohol just to be sure. On my other orchids I found predatory mites and beetles should I spray them as well? even with the predators? also does anyone have experience with buying predatory mites?