Spider Mites: Spider Mites Strike Back

[BrassavolaStars]

Hello all,

I was beginning to believe I was winning the battle with the mites until I took a flashlight around the greenhouse. Webs! Everywhere! Nearly on every plant! Stretching even as far as 4 feet.

It was suggested to me that the best course of action would be to move every plant outside and wash each one with a dish soap mixture. Does this seem like a good plan of action?

Some people also recommend alcohol. The Bayer and Azamax no longer seem to be enough.

In a turn of good news, my brassavolas, miltoniopsis, brassias, and many angraecums are about to bloom. Should I post photos? The first ones of the cohort will be the miltoniopsis, Angcm Grandalena, Angcm Lemforde White Beauty, and B. Hugging Stars.

Oddly, the Lemford white is attracting ants to the buds. Do the ants harm the buds?

[SouthPark]

I'm thinking that the azamax should be enough. Just mix again to the recommendation concentration - in a garden pump sprayer - with adjustable spray nozzle, and spray all the leaves/stems (under the leaves too). The aim is to reduce their numbers significantly. And then repeat the spraying a few days later or something.

Ants do hang around in the wild and walk onto everything.

They generally don't harm the orchids - but could possibly carry unwanted stuff (spores or something) on their bodies ..... carrying it onto the plant from somewhere else. I don't worry about ants too much. I know they make nests in my pots of scoria heheheh. And wouldn't be surprised if they bring some nutrients into the scoria too.

[sam1147]

Well. IF / When you will get tired of all the light stuff like Neem & soap etc.also parts of your plants
will eventually die, then I suggest you will start using real miticides.
In my opinion Best is Abamectin (Avid).Also do rotate with Bifenazate and/or Etoxazole and / or Dicofol .Use ALL according to the lables!!!

[bejay]

please don't take spider mites lightly. I lost my entire phal collection several years ago. Neem and Bayer (from big box store) didn't work for me. Just got back to renewing orchid growing as a hobby. How is the humidity in your greenhouse? I would go straight to the "strong" stuff to control those critters, they went through all my phals quick...had no time to try the strong miticides.

[Roberta]

First, please post photos when things bloom! Either under the Orchid Alliances forum, or Plants in Bloom thread.

Ants don't harm the plants or flowers themselves... but they "farm" aphids, that certainly do. So, ants are something that you don't want around the orchids.

With a mite infestation like that, don't mess around. Inside the house, you might not want to use miticides but in a greenhouse, go for it. I use bifenthrin ... specific for mites (I mostly use on the Catasetinae because that's where I have the issue).
Here's an online source. bifenthrin - Do It Yourself Pest Control . They're a good go-to source when you want to go beyond the Big Box store remedies.

[estación seca]

Spider mite webs don't spread 4 feet. Do you mean webs are spreading from one point to another 4 feet away? That would be spiders, which are good to have in the greenhouse.

Spider mite damage could cover 4 feet of plants on a bench, but the webs are worse on the undersurface of the leaves. Your greenhouse is humid enough you are worried about fungus issues. Be sure you really have spider mites before you start spraying highly toxic chemicals.

You can't ever get rid of spider mites. They live in the garden around your greenhouse. Control is needed. Once the population is knocked way down, use a vigorous spray of water under all your leaves once a week when you water. They can't crawl back onto the plants.

I don't know how many plants you have. I would mix up soap solution and spray the whole collection.

[BrassavolaStars]

Originally Posted by estación seca

Spider mite webs don't spread 4 feet. Do you mean webs are spreading from one point to another 4 feet away? That would be spiders, which are good to have in the greenhouse.

Spider mite damage could cover 4 feet of plants on a bench, but the webs are worse on the undersurface of the leaves. Your greenhouse is humid enough you are worried about fungus issues. Be sure you really have spider mites before you start spraying highly toxic chemicals.

You can't ever get rid of spider mites. They live in the garden around your greenhouse. Control is needed. Once the population is knocked way down, use a vigorous spray of water under all your leaves once a week when you water. They can't crawl back onto the plants.

I don't know how many plants you have. I would mix up soap solution and spray the whole collection.

I have approximately 200 plants. I bought plant based dish soap. Is that safe to spray. I was told to get ivory soap but that was unavailable.

I do have avid but I’m reluctant to use it as the label is very menacing in terms of toxicity. The webs are going between points about 2 feet across and then connecting with webs also going 2 feet across like some sort of web network. The webs also tend to end up leading to the underside of leaves.

[SouthPark]

See if you can get a jeweller's loupe hand lens magnifier - the ones with a little built in LED illumination light ...... and see if you can spot any spider mites ------ to get a positive visual ID.

[Leafmite]

I really hate spidermites. I had a really bad infestation of them one year and so I grabbed my can of olive oil cooking spray and sprayed all my plants very well one evening, then washed the plants very with warm, soapy water the next day...I didn't see spidermites for another three years. Unfortunately, that solution is a pain because getting the olive oil off of each plant is very time consuming.

Neem oil is a better option. Get the really pure stuff and then mix it according to instructions (usually water and some dish soap), then spray the plants heavily (shaking often to keep the oil mixed). You will need to spray them twice a week for a few weeks to make certain you get them all. Neem oil doesn't need to be washed off the plants like olive oil and it does a nice job of suffocating the mites. Ray also has mentioned a product (also derived from the Neem tree) that is very effective on mites. Neem oil is also completely safe.

The problem with mites is that they become resistant to the pesticides.

Good luck!

Opps, noticed that many say that Neem oil wasn't working for them. If you do use the Avid, you can always buy protective gear before spraying the plants, then take a shower and rinse your clothing very well after (just in case any gets thought the protective gear). I had fruit trees for many, many years and had to spray Malathion and Captan every two weeks, all summer long. I do not miss doing that.

[estación seca]

If you have webs stretching 2 feet you have spiders, not spider mites. Leave them be. They will eat harmful insects. Spider mites start attacking undersides of leaves. They leave silvery cobwebs there. They are most active during periods of warm temperatures and low humidity. If you have a very humid greenhouse it is highly unlikely you have an extensive spider mite problem.