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carol222_gw

Thrips - best insecticidal spray

carol222
15 years ago

I saw some spilled pollen on one of my AVs on Thursday. I looked at the flower under the microscope and sure enough, saw a little hole chewed into one of the anthers. I also found spilled pollen on a barely opened Strep flower. So I sprayed everything with Seven, the only insecticidal spray I had around. I put them all in plastic bags overnight.

So now I have a few questions:

1. I couldn't find an insect on any flower microscopically. Even the AV with the hole in the anther. None of its other flowers had holes or spilled pollen, and it was in full bloom. Am I right to assume it's thrips?

2. After you spray, do you let it dry before you put it in the plastic bags. I didn't, assuming that the evaporation of the spray might help kill more bugs, but doing that did damage some of the streps a bit.

3. What is the best insecticidal spray for thrips. I know I have to spray a couple more times, so I thought I should find out what the best one was.

4. Do I need to drench the soil to kill larvae?


I did leave the buds on one plant - a Chirita I raised from seeds I got from the Gesneriad Society's mixed gesneriads. I have waited two years to see the blooms so I can identify the plant. I will cut them off once I see what it is. I think they will open some time this week. I can't bring myself to cut them off so close to finally knowing what this plant is. It was hard enough to cut off all the other plants' flowers. January has always been my biggest blooming time, and there were so many flowers to cut.

Carol

Comments (10)

  • robitaillenancy1
    15 years ago

    Yes, Sevin (Carabyl) would be one of the best to handle thrips.

    Neem Oil would have helped.
    Talstar (synthetic pyrethrin)
    Cyfluthrin granules (time-released insecticide lasts up to two to three months. Slow acting but it will control thrips and other insects.

    Dimetoat 25 WP
    Concerve
    Avid

    Any of these will control thrips. But all this is overkill if there is a possibility that you do not really have thrips.

    The easiest method yet the hardest to do is to disbud every flower and bud in your house. If thrips can not eat they die. A few may go into the soil for a time looking for food and a safe place to hang out.

    But generally speaking just disbudding will control these awful creatures that carry Impatience Necrotic Spot Virus which is deadly to most plants.

    For more information see ebay for my book Insects, Pests and Diseases of the African Violet Family.

    Nancy

  • carol222
    Original Author
    15 years ago

    Thanks, Nancy,
    I have your book, but lent it to one of my students, so I wasn't able to consult it!
    I understood that thrips also ate the leaves, too. It would reassure me a lot to know that just disbudding can go a long way to controlling them. I have Avid, but hesitate to use it, as it gives me a bad contact allergy - if I touch the plants bare-handed for several days after, I get a rash.
    I couldn't figure out why I could not see any thrips, but also don't know what else could/would chew a hole in an anther.
    Carol

  • irina_co
    15 years ago

    Carol -

    streptocarpus spreads its pollen, it doesn't need thrips help to self pollinate. AV's don't.

    I do not know what is the residual action of sevin. Avid loses its killing power in 24 hours. ( I would say - use latex gloves around your plants after the treatment in any case.)

    Thing is - if you missed thrips, eggs or pupas - they will come back. So - you need a repeat treatment - better 2 - week - 10 days apart. It is hard to kill off pupas - they do not eat - and they can hide in a soil.

    Last time - a friend gave me a bit of Pylon - and it has 30 days residual action and it is translaminar - means it gets into the plant tissue - so 1 treatment did them all. But - it is so ungodly expensive - that it is better if club buys it to share.

    So - did you find out what kind of chirita you grew?

    I would let 1 purple AV bloom and watch it like a hawk - just to monitor if you have them. Purple attracts them.

    Nancy is absolutely right on disbudding. If the thrips is sitting inside the anther and chomping on the pollen - you wouldn't be able to reach it. Even systemic doesn't reach flowers to create enough concentration to kill them.

    Make a good photo of your chirita - disbud and spray it.

    Good luck

    Irina

  • nwgatreasures
    15 years ago

    And these are sprayed in the soil, on the plant leaves, etc??

    I disbudded way before holidays (although with the MRSA, I can't really remember when but could look it up on here) and then I sprayed with Conserve.
    I have removed any buds that were creeping in for several weeks now and examined them wtih a close eye. I've seen nothing....I went off to a women's retreat for 2 days and came home today to see one of my standards with those darn bugs on the leaves.

    I guess I'm spraying again tomorrow and continuing to disbud.
    :::sigh:::

    Dora

  • irina_co
    15 years ago

    Dora -

    you need to do it 3 times. Conserve falls apart in 24 hours - which is good for the house and home- but whatever bugs escaped - they will continue procreating. Thrips life cycle takes from 8 to 44 days - in cold weather. So supposedly your home is moderate. You repeat it 3 times so every new batch that hatched from the hidden eggs - gets nailed before they plant new eggs.

    The next thing - they can develop resistance to Conserve. so next whole treatment (3 times week apart) - should be done with a different insecticide.

    The good part - you reduced the population significantly. Treat them before they will be all over the place.

    Irina

  • nwgatreasures
    15 years ago

    Irina,
    Thanks for helping me learn how to best tackle this nusance :/

    Other than conserve - (and I did see the suggested list of chemicals) which one would be your personal/professional choice of spray to use? If I'm going to have to add another one, I would prefer a recommendation.

    Our society will be purchasing Nancy's book for our club but until I get that, I am relying on experience here. I want these things gone quickly and permanently (I know....they could always come back but you know what I mean)

    What opinion/experience do you have with the marathon? granules that go on the soil surface? What does that do for thrips?

    Dora

  • irina_co
    15 years ago

    Dora -

    I think everything Nancy mentioned - could work - just be persistent. It is easy to kill the thrips, hard to kill them all.

    last thing I tried was Pylon- and because it is systemic + miticide - it took care of them in one shot - but $500 a bottle... A friend gave me a teaspoon - and it took care of the whole collection.

    I use Marathon in my soil - because I had a bad experience with soil mealies. BAD. Just recently I got several strep babies - and I potted them in Oyama pots - was lucky. Found mealy bugs in them a week ago. At least they stayed contained in the pots. Even I had Marathon added to the soil - but Marathon wears off in 3 months or so - and the traded streps had eggs in their soil. So - I found just a bit of them. But in every pot from this batch.

    In any case - Marathon would not reach the bloom to kill the thrips that drilled the hole in still closed bud and is sitting here and chomping on pollen. So - it possibly for some time it will suppress the thrips - but not eradicate them - and you definitely need to disbud up to the last itti-bitti small bud. And you need to keep the plants disbudded all the the time you spray 3 times - because it is just impossible to nail them there - just as Nancy recommends.

    Good luck

    irina

  • hwjec_yahoo_com
    12 years ago

    I am having a terrible time with thrips on my rose bush and I think they are getting on some other plants because parts of them are slowly dying for no apparent reason. I have sprayed with Sevin twice on my rose and we even had a heavy rain several days ago but they are still not gone!!! Please give me any suggestions.

  • clawrence1
    10 years ago

    I have thrips on my AVs..never had them until they shared a window shelf unit with an Easter Cactus blooming it's head off that spent the summer outdoors...having said that, I've been spraying with insecticidal soap for about 2 weeks, every few days and still I see thrips. I have a Hot Shot Pest Strip, cannot be used indoors, BUT I have a room with a plant light where I can TENT the offending plants, with the pest strip enclosed for a week or more, if necessary. Do you think this might work? I've already removed blooms and buds but there are tiny new buds forming and I hate to cut those as well. Will the pest strip and tent idea work or am I wasting my time?

  • irina_co
    10 years ago

    Yes - you are wasting your time.

    They fly quite well -so presumably they are everywhere. Eventually they will be on every plant in the house.
    They go through several stages - and one of them -in a soil - so no amount of spraying is going to reach them in a soil or inside the buds.

    Seems that AVID, Merit or Conserve (some of populations of western thrips already developed resistance to it) - is the way to go - repeated spraying of all plant material in the house - 3 times week apart -and removal of the buds - and 3 weeks later - you will be out of trouble. if you have fish - make sure to cover the fish tanks during the spraying. Or do it in the garage.

    I.