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greenhouser

Spider mites on Tomatoes

greenhouser
16 years ago

What have you people found most effective for spider mites on tomatoes grown in your Greenhouse? The organic insecticides don't work. Hosing them daily for a week didn't work either. The systemic I use on other plants can't be used for food crops.

Comments (38)

  • pcan-z9
    16 years ago

    Spidermites ....I just detest those things. My sister "surprised" me by buying me an orchid at the flea-market a few months ago. While I wasn't home she hung it in_my_GH. I was surprised all right. That thing was crawling with red spidermites. I flew into panic mode. I got rid of them off the orchid (Dendrobium) with the water method. I hit the leaves top and bottom with a sharp stream of water everyday for a month. It never spread to the rest of the plants in the GH, so I was just lucky I guess and got it out of there in time. I'm sure you know this but watch your Dend's. spidermites of all kinds LOVE them, and if they are in the same GH with the tomatoes, it's almost a for sure thing.

    I don't grow tomatoes in the GH, and I don't know if this is a kooky idea or not, but a friend of mine swears by tobacco juice. She makes a weak tea out of chewing tobacco and soaks the infested plants down with that for a few days. I've never tried it and I would NEVER try it with orchids, but on tomatoes - who knows?? Like I said, it seems to work for her.

  • stressbaby
    16 years ago

    Spider mites are quite sensitive to a variety of relatively nontoxic controls. Neem oil works well. Soap sprays also work, but you should know that soap sprays with detergents are quite phytotoxic to young tomatoes. Permethrin/pyrethrum also works. Increasing humidity might help.

    SB

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  • greenhouser
    Original Author
    16 years ago

    I've used Permethrin/pyrethrum and these spiders are immune to it, also another I forget the name of. It's also almost imossible to get the powder or a spray up UNDER all the leaves where these little monsters are. I just bought Neem oil and will try that with a few drops of dish soap.

    Yes, I have dens in there and Impatiens, better known as spidermite-magnets. I spray them all with the systemic so they're clean so far.

    Thanks for the info.... I hope the Neem oil and soap work. These are older plants and the sun isn't on them all day so I'll try it.

  • greenhouser
    Original Author
    16 years ago

    stressbaby

    Neem oil has no effect on the spider mites... anything else you can think of?

  • ladylotus
    16 years ago

    Sheri,

    The Neem oil and Insecticidal soaps should work for you. This type of chemical control will only work by contact. So, you will have to be sure you are generously applying these onto your plants. It is imperitive that the plants are thoroughly covered. I've had success using Neem oil and Insecticidal soap, but I had to be persistent and continue using these every 3 days. As I understand it the lavae are hatch every week and if you miss a spot on the plant those little buggers will just keep multiplying.

    Sheri, if you have a lot of plants I would suggest you fill a sink or large bucket with the neem oil solution mix, put cut cardboard or something similar over the soil, while holding the soil in the pots, invert the pot so you are dipping the plant into the solution. I've done this in the past. I cut the cardboard like a donut, cut a slit on one side of the cardboard as to allow it to open and fit around the plants stalk. It takes a bit of patience. he he But is does work.

    Once you've rid the little buggers, try using the Bayer All in One or 3 in 1 systemic solution. I love it and use it on all my plants a few weeks before I bring them into the house.

    Good luck!
    Tj

  • oakhill (zone 9A, Calif.)
    16 years ago

    SB is correct. Neem oil is effective on mites, provided the label directions are followed. It is registered for use in California, which means that it was tested for efficacy and passed. CR

    Here is a link that might be useful: neem oil label

  • greenhouser
    Original Author
    16 years ago

    ladylotus

    These are GH tomatoes 5' tall in tubs that weigh more than the average person can lift with 2 plants to a tub. They can't be carried to a sink or laid on their sides so all leaf surfaces can be covered. Covering the undersurface of such thickly leafed plants is almost impossible short of using the water wand on the hose. I've washed them down and under the leaves with the hose when the temp allows, but the mites are right back before sundown. The Neem oil w/soap made little difference. And yes, I followed the directions on the container.

    How many days did it take before you noticed a the mite population was devistated on your toms?

  • greenhouser
    Original Author
    16 years ago

    ladylotus

    On the systemic and tomatoes. Systemics are not supposed to be used on food plants. That's for ornamentals. I use it on my geraniums and impatiens.

  • greenhouser
    Original Author
    16 years ago

    I read several websites this afternoon and Neem oil isn't always effective. I followed the directions on the container and there was little effect on the mites. Several hours later, just like after a good hosing, they were right back and quite alive. The brand I Bought is "GreenLight" the only one I could find locally. The mix is 2 Tbs per gallon. I use a measuring spoon.
    Keep in mind just because something passed a test a few years ago doesn't mean it still works. Here in TN there are less and less effective products because the insects and bugs are developing immunity to most of them. Just try and find something that kills Japanese Beetles for example! Last spring I threw away a bunch of Insecticides that were useless inclduing Seven Dust, which is still being sold and passed the tests also - a long time ago. Everything is immune to it.
    When our dogs got infested with fleas and ticks, NOTHING worked but the dangerous foul smelling Paramite rinse and a hormone spray of the house to keep the flea eggs from turning into fleas. When I was a kid anything my mother picked up at the store and sprayed our dogs with worked.

  • oakhill (zone 9A, Calif.)
    16 years ago

    Azadirachtin, the active ingredient in neem oil, is primarily an insect growth regulator , and for mites, a repellent. It generally does not kill on contact, but prevents pests from maturing and reproducting. The effectiveness is observed over a period of several weeks as the population decreases. It would be expected that the pests would still be alive within hours of spraying.

    Here is a link that might be useful: neem oil

  • highjack
    16 years ago

    Google Floramite for spider mites, available at Rosemania. I don't know if it is safe for food plants but it is for ornamentals. It kills on contact plus kills the eggs. We just eliminated them from daylilies in pots before they spread to the orchids. We had used multiple products, including neem oil, with no success.

    Good luck - Brooke

  • oakhill (zone 9A, Calif.)
    16 years ago

    Good to know that Floramite SC worked well for you. It is registered in most states for use on greenhouse tomatoes, except for the small "grape" and cluster types. One quart, the smallest container size, about $250.

  • greenhouser
    Original Author
    16 years ago

    Hijack

    See below. It's ok for use on GH tomatoes but who can afford it at $329.95 qt.

    http://www.bghydro.com/BGH/itemdesc.asp?ic=PCFM32&eq=&Tp=

    The Neem oil may work in time but by then the plants will be too far gone.

    Floramite and GH toms:

    http://www.cromptoncorp.com/servlet/ContentServer?pagename=ck/pressrelease&c=ck_article&cid=1077545323740&type=whatsnew

  • greenhouser
    Original Author
    16 years ago

    It's well over a week now with the Neem oil and soap. The plants continue to deteriorate, leaves yellowing and turning a sick purple near the bottom. Grown stopped completely. If the mites are unable to reproduce when exposed to this product, someone failed to tell them - or they've become immune or mostly immune. Have you used Neem oil on your tomatoes or are you going by what you read online?

  • highjack
    16 years ago

    The Floramite is expensive but so far effective. Who knows down the road but I will keep watching.

    I was shocked when I found the mites because I thought they appeared in hot, dry conditions. At night, the G/H runs in the 90% range, lower in the daytime if the sun is out. I spent years growing under lights during the winter and always expected to get the mites inside. Never had them until this year, in the humid G/H. Go figure.

    Brooke

  • stressbaby
    16 years ago

    Greenhouser, you are experiencing some of the challenges of growing winter GH tomatoes!

    It sounds to me as if you may have a problem other than just mites. Spider mite damage gives a characteristic, very fine speckling of the leaves. Purple leaves in toms occur with phosphorus deficiency. Phosphorus deficiency and slow growth are in part a result of cold temps. What temps are you keeping? And what kind of soap spray are you using? As I said, some soap sprays contain detergents and are phytotoxic to toms. How often are you using it?

    Back when I grew winter GH toms, I could control all of the tom pests with Neem and soap sprays.

    Happy Thanksgiving, all.

  • greenhouser
    Original Author
    16 years ago

    stressbaby

    Today I see some improvement in the toms. No new webs and few specks or spiders. :)))) I really drenched them again anyway and turned the humidifier up to 80%. I think the constant Neem oil and higher humidity are getting to them.

    They're getting a fertilizer with Phos and only the toms with spiders have the odd purpling between the veins.

    Nights have a low of 62/63F and days can get into the low to mid 80s.

    The soap was some leftover stuff from a neighbor. It was something "organic". I only had a few sprays worth. I don't plan to by more of those "soaps."

  • greenhouser
    Original Author
    16 years ago

    highjack

    They have been a problem on Impatiens for years now. The systemic was the first thing since Kelthane that worked. I can't find Kelthane anywhere anymore. In the area were I live, farmed for years, the insects and bugs are immune to just about everything you can buy in the stores. Ticks, chiggers and fleas are also having a field day. Nothing fazes the flower destroying Japanese beetles. I don't know what's going to be 25 years from now. I think they really need to concentrate on insect/bug/spider hormones and plant immunity systems. The chemicals will be worthless or so toxic we'll be dropping dead just eating the food that was sprayed.

  • buyorsell888
    16 years ago

    Someone suggested chewing tobacco tea, this is NOT a good idea for Tomatoes. Causes Tobacco Mosaic Virus. Even having chew or a pack of cigs in your pocket in the greenhouse with tomatoes can be a problem. I remember my horticulture teacher taking all the chew away from the cowboy wannabes in class years ago because we were growing tomatoes in one of the greenhouses.

    Spider mites do not cause the severe damage being described in this thread. Their damage is subtle and would take months and months to actually do so much harm.

    Likely all the spraying of various chemicals is harming the foliage.

    Over spraying is more harmful than following directions.

    Kelthane was taken off the market then brought back on then taken off again because of human health concerns.

  • greenhouser
    Original Author
    16 years ago

    buyorsell888

    Under the right conditions spider mites reproduce rapidly and sap the plants to death unless stopped. It doesn't take months. At least that applies top those we have here in TN.

  • ole_dawg
    16 years ago

    Well it would appear that some of the more colorfil entrys have been deleted.
    Greenhouser have you tried Hot Pepper Wax?

    Jack

  • greenhouser
    Original Author
    16 years ago

    What's hot pepper wax?

  • oakhill (zone 9A, Calif.)
    16 years ago

    "The organic insecticides don't work" Actually there are several effective miticides registered for use on greenhouse vegetables. The following are also allowed on "organic" produce: Pyrellin, M-pede, and Cinnamite.
    To answer the question posted, "hot pepper wax" is a concentrate of cayenne peppers. Since we have already discussed the fact that neem oil works by inhibiting reproduction of mites, any one week trial for mites, that have up to a three week life cycle, is not relevant.

  • greenhouser
    Original Author
    16 years ago

    A Google search for Pyrellin (2.5g for $300/unaffordable), M-pede ($80 a gal/unaffordable), and Cinnamite (contact action only/couldn't find a price or supplier). I assume it's somewhere between $80 and $300 which is unaffordable for those of us on a limited income. Of course there is no guarantee they'll repel or kill these beige mites. It seems all work done was with the 2 spot mite.

    Since you recommend these products can I assume that you tried at least one of them yourself? I was hoping to find someone who actually used something that worked for them.

    Remember, just because something is registered doesn't mean it works. Not one registered flea product worked on our dogs. We had to use the dangerous Paramite dip and spray the entire house (furniture, closets, everything) and yard with a flea hormone spray. That was after wasting several hundred dollars on other products (soaps, sprays, flea collars, flea dips, citrus repellents, Dursban sprays, Pyrethrin, Sevin Dust, an exterminator etc.) first.

  • stressbaby
    16 years ago

    Greenhouser,

    By your account, you have Tennessee superbugs capable of surviving a nuclear war. So who cares if cuestaroble had good results with Pyrellin, it may not work for you, right? And now you assume that you have some different kind of spider mite. I don't get it.

    Ortho Systemic (acephate) is an organophosphate pesticide, in the same class as Di-syston (disulfoton). Both of those are acetylcholinesterase inhibitors, a class of pesticides of which Sevin (carbaryl) is also a member. Now if I know a bacteria is resistant to one penicillin, I don't prescribe another penicillin, I look to another drug class and try to pick an antibiotic with a different mechanism of action. No rocket science here, it is common sense. If in fact you have a pest that is resistant to carbaryl and disulfoton, you are asking for trouble by relying on acephate.

    Post pics of your mites, so we can see what they really are. Post pics of your tomatoes so we can determine whether they have something else wrong with them which is making them susceptible, as buyorsell888 suggests. And start hammering those spider mites with the cheapest treatment of all, blasts of water.

    Sincerely interested in your pest/tomato problem,

    SB

  • ole_dawg
    16 years ago

    GH,
    The hot pepper wax I was referencing is from "Neptunes Harvest". With regard to your comment about fish/seaweed emulsion. The smell goes away and once you wash your hands they smell OK as well.

    Have you tried Ultra Sonic waves yet. I hear that is good for just about everything except your ears.
    I used a unit I bought on Ebay and it did cure my ingrown toe nail so it just might (pun) kill you mites.

    If all else fails juse pull them up and try again next year.

    1eyedJack and the Dawg

  • oldbusy1
    16 years ago

    Greenhouser,

    thought i'd post in this thread for awhile. Hopefully the Malathion dust will knock your spidermites out. Now for caterpillers on other crops i use Dipel Dust. It is only toxic to caterpillers.cabbage worms,cornborers,tomatoe hornworms,etc.

    I manily have problems with cucumber beetles,blister beetles in my summer garden. Malithion spray usually keeps them in check.

    My wife had daylillies that were infested with spidermites and the liquid malathion took care of them real fast.i gave them a good soaking.

    If your tomatoes are already on there way down it may be too late to do much good. But it might kep them from spreading to everything else.

  • greenhouser
    Original Author
    16 years ago

    * Posted by stressbaby z6 MO (My Page) on
    Sun, Dec 2, 07 at 11:13

    Greenhouser,

    By your account, you have Tennessee superbugs capable of surviving a nuclear war. So who cares if cuestaroble had good results with Pyrellin, it may not work for you, right? And now you assume that you have some different kind of spider mite. I don't get it.

    I am glad there are people like cuestaroble who can afford $300 for Pyrellin. Please don't assume everyone can. It may or may not work for me but I don't have $300 to find out. The superbugs here are not of my making. The problem existed when I moved here years ago.

    Ortho Systemic (acephate) is an organophosphate pesticide, in the same class as Di-syston (disulfoton). Both of those are acetylcholinesterase inhibitors, a class of pesticides of which Sevin (carbaryl) is also a member. Now if I know a bacteria is resistant to one penicillin, I don't prescribe another penicillin, I look to another drug class and try to pick an antibiotic with a different mechanism of action. No rocket science here, it is common sense. If in fact you have a pest that is resistant to carbaryl and disulfoton, you are asking for trouble by relying on acephate.

    So I'm asking for trouble using a product what WORKS on my Impatiens? It's the only product I found to work. What do you suggest I do, start ordering hundreds of dollars worth of pesticides online in hopes I find another that works on Impatiens and not burns their leaves?

    Post pics of your mites, so we can see what they really are. Post pics of your tomatoes so we can determine whether they have something else wrong with them which is making them susceptible, as buyorsell888 suggests. And start hammering those spider mites with the cheapest treatment of all, blasts of water.

    I don't have a camera that takes closeups. All I have is an old HP digital camera. Cameras that take closeups of something as tiny as a mite costs hundreds of dollars. I can take some pics of the plants tomorrow in the daylight. After the first spraying with Neem oil the leaves started to turn a strange yellow and purplish brown. I hope my old camera can capture the color of the leaves.

    Sincerely interested in your pest/tomato problem,

  • greenhouser
    Original Author
    16 years ago

    cuestaroble

    Thanks for the info on Neem oil. Since I have it I'll keep using it. I also bought a pressure sprayer and have been spraying the toms with clear water twice a day. I can't use the hose because the water is too cold this time of year.

  • greenhouser
    Original Author
    16 years ago

    busy1

    I never made it to Tractor Supply this weekend. At this point I think the plants are too far gone. To add to their misery it's been cloudy for the past few days. I've been spraying under the leaves with a hand-pump pressure sprayer and the webs and numbers of spiders have definitely dropped. I'm wondering if I should cut off the tops which received the most spider damage and let new shoots grow. What do you think? I've seen their numbers drop before just to zoom back up again..... I'll take pics tomorrow of these pathetic plants.

  • oldbusy1
    16 years ago

    I dont know what to suggest except anything is worth a try at this point. If you have anything else in the greenhouse , those spidermites need killed to stop the spread.

    Dont get discouraged.

  • ole_dawg
    16 years ago

    When you go to take the photos use a tripod if you have one or something else to steady the camera. Use the highest resolution you can. THEN SEND ME A LARGE FILE VIA ATTACHMENT to an email and I will run it thru PhotoShop and try and blow it up enough for us to see.

    Last year I tried to grow tomatoes. THey fllooped. I took a Disc with photoes and a couple of leaves to the County Agent. I had just plain old mites. I will look for the stuff I used to kill them. It did, but the toms were to far gone. That is one of the reasons I did not grow this year.

    1eyedJack and the Dawg

  • greenhouser
    Original Author
    16 years ago

    ole_dawg

    Thanks. I already took the pics. I didn't see any mites or webs this afternoon. I have PhotoDeluxe to adjust the size of pics.

  • sandy0225
    16 years ago

    You need to rotate sprays, and not use one that kills the same way twice in a row so that your critters can't get resistant to it. Since you used neem this week, use pyretherin next week, and something else next week. Organic or not, you have to rotate or you'll get resistance.
    Also, you can pick every single leaf off those tomatoes and give them a little trim and spray them with a fruit tree type dormant oil spray. That's a last resort measure, but it will work. They will grow leaves back if they're not too far gone.
    I had to take all the leaves off a brugmansia once to get rid of them with a heavy oil spray.

  • greenhouser
    Original Author
    16 years ago

    sandy0225

    Thanks Sandy but I'm not putting any more money into them. I cleaned them off a few times with a hand pump pressure sprayer, then literally drenched them in Neem oil. I haven't seen any spiders on them in some days now. They're looking a little better. I knew about alternating sprays.

  • rich29837_aol_com
    12 years ago

    I have been struggling with these pesky bugs for 10 years now. I have tried various things that have worked off and on, but the only thing that has been consistant is a product called No Spider Mites. It is all organic and doesn't leave harmful chemicals on my plants. Maybe that will work for you. I love it.

    Here is a link that might be useful: How to get rid of spider mites

  • vici1
    8 years ago

    Diatomaceous earth (DE) is natural and the silica destroys their crustaceous shells. Dilute the DE in water and spray on the leaves, when it dries it will be effective. DE is also a good plan fertiliser which is shown over time to help the plant build up resistance to bugs. There I'd an article on the Web "a review of silica and it's benefits for plants" very informative and natural so no chemical toxins. They food grade DE is safe for humans and animals as well with many benefits which basically will replace those hundred and one vitamins of which most are synthetic anyway and cannot be absorbed by the body.

  • Gundel Palacsinta
    last year

    Nicotine. That was the first which really worked to me, I had to spray my plants - tomato but they love peppers even more) in every two week or so or they came back. I put some plants outside from the green house, that helped but I couldn't put out every one of them. As we both smoke and even my granny used nicotine I am not over worried about it, more worried about its price. On the other hand, for white flies terrible amount of sticky tapes hanging on the plants which helped.

    I think the poisonous effect of nicotine is overestimated, slugs don't mind chewing on tobacco plants, in fact they don't even mind chewing the Aztec tobacco plant (highest nicotine content), just wear gloves when spraying as it is a contact-poison and big drops can fall to your skin, but part of the story we have cats and absolutely nothing happened with them what I can't tell about when we used permethrin (for another problem) which absolutely poisonous to them. Wear gloves, soak tobacco (2 boxes of strong cigarettes' contents) in 1 liter water for a day or two, then filter it and put the liquid into a spray bottle, kick the cats out of the greenhouse / conservatory (if you have) while spraying and wait till it dries on the plants.