Author Topic: How to control a thrips infestation  (Read 1193 times)

AndrewAZ

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How to control a thrips infestation
« on: October 04, 2022, 12:08:40 AM »
I think I brought them onto my property after buying some rose bushes at the big box stores.   I've tried a whole bunch othigs, trimming off infected branches,  need oil.  Been trying for over a year and no luck.

pagnr

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Re: How to control a thrips infestation
« Reply #1 on: October 04, 2022, 05:25:55 AM »
I had thrips on Persimmon trees in containers. It is important to spray the undersides of the leaves, where the larvae are clustered.
See if you can see larvae on the leaf undersides. These can be easier targets than the adults.
You need to rig the sprayer nozzle to point upwards, possibly a long wand will help ( more so if you are also fighting Gnomes and Trolls ).
Also they have a life cycle where they moult in the soil, then reemerge as adults, so you need to repeat the spray process to interrupt the lifecycle.
You can knock a lot of larvae off with a water spray.
I used Pyrethrum and Neem sprays. Possibly Hort soap sprays would work.
It useful to have a spray nozzle set up like spray painting every leaf, low volume, mist, wide fan.
As the larvae were moulting in the pot soil, a fertiliser application with wetting agent, a surfactant ( basically a safe detergent ) seemed to interrupt them too.

Millet

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Re: How to control a thrips infestation
« Reply #2 on: October 04, 2022, 10:57:21 AM »
Pagnr, gave you good information.  I use a horticulture oil spray for both thrips, scale, mealy bugs, and aphids,  Works well.

jbclem

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Re: How to control a thrips infestation
« Reply #3 on: October 12, 2022, 07:51:20 AM »
I have what I think are thrip nymphs/larvae, visible with a handheld 10-15x LED microscope.  They are torpedo shaped, translucent enough so that you can watch their excrement go from inside to outside, dropping as lines of small dark green blobs.  They are on my seedling vegetable plants in an indoor growing area and are hard to find because there aren't that many of them compared to the number of lesions (and blobs) they create.  I'll occasionally  spot one or two in an area where there are lots of the dark green excrement blobs.  They are in the same size range as spider mites, but move around a lot more than the spider mites and are no where near as numerous.  I've never seen their eggs or an adult thrip.  Does it sound like these are thrip larvae?  I've looked them up and some photos seem to confirm this.

I've been spraying them with Safer's Soap and that seems to work...but they keep coming back. Would Safer's Soap act as a safe surfactant if I mixed it with fertilizer to use in the soil as mentioned? 

Pagnr, could you tell me which spray nozzle you've found most useful for reaching the underside of leaves?

pagnr

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Re: How to control a thrips infestation
« Reply #4 on: October 12, 2022, 08:50:10 AM »
Pagnr, could you tell me which spray nozzle you've found most useful for reaching the underside of leaves?

Using a small 10 litre sprayer with a pumped handle to pressurise, pretty common type.
I found it most useful to have an extension to double the wand length and/ or also a longer hose from the tank to the wand.
It makes it easier to wave around, and also not move the spray tank so much, or have to lift it.
Also an elbow bend on the nozzle end, easier to point upwards.
If you can adjust the spray pattern of the fitted nozzle to a wide fan, that can make coverage easier without having to look too hard.

Irrigation mister nozzles can give a wide fan, with less spray volume used. Might need an inline filter fitted to stop clogging the finer nozzle hole.
Or be careful when mixing to strain out lumps, and shake tank to prevent slugs forming.
Brass nozzles on screw threads can be fitted to the plastic nozzle on the sprayer.

Not sure I have seen Thrip larvae moving much, seem to cluster under the leaves on the main vein. Infested plants are often silvery looking from the feeding activity. Adults and larvae were present at the same time. However there are a lot of species, so couldn't be sure they all behave like that.

franklazar26

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Re: How to control a thrips infestation
« Reply #5 on: October 15, 2022, 08:02:18 PM »
I had thrips forever on my citrus, spinosad was the only thing that ever worked for me after trying all types of oils and other things. Spinosad worked amazing.

Tropicaltoba

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Re: How to control a thrips infestation
« Reply #6 on: January 17, 2023, 08:09:44 PM »
New to the forum but Iíve tried pirate bugs with a lot of success. I know ďorganicĒ can get kind goofy  but Itís really cool, they will actually go and stab (for sport) the thrips like a rhino with their horn. They actually kill more then they eat. Iíve used them along with purple flash pepper plants (nice looking perpetually blooming shade tolerant ornamental) as a banker plant. The thrips also attack the pepper flowers instead and the pirate bugs can use the pepper pollen as a food source if there are not bugs left to eat.

AndrewAZ

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Re: How to control a thrips infestation
« Reply #7 on: January 18, 2023, 12:31:44 AM »
Thanks for the tip!  Do you know where I can buy those bugs?  I also heard the smell of marigolds can also repel thrips, s am throwing some seed around my roses, as they are getting hit, too.

Vegan Potato Man

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Re: How to control a thrips infestation
« Reply #8 on: January 18, 2023, 01:04:38 PM »
I'd suggest looking into beauveria bassiania. Its an entomophagic fungus that causes white muscardine disease in many pest insects.

Sold as botanigard, kind of pricey though.

AndrewAZ

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Re: How to control a thrips infestation
« Reply #9 on: January 18, 2023, 11:02:34 PM »
Do you spread it in the soil?  On the plants?

Vegan Potato Man

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Re: How to control a thrips infestation
« Reply #10 on: January 19, 2023, 10:41:18 AM »
Do you spread it in the soil?  On the plants?

BB can be applied with a sprayer. Make sure to target leaf undersides and spray during cloudy/rainy conditions. Strong sunlight will damage the spores. I believe it is a soil microbe but I'm not certain if it will persist. I would assume to some extent.

Millet

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Re: How to control a thrips infestation
« Reply #11 on: January 19, 2023, 02:28:25 PM »
Actually thrips are among the easiest insects to control.  You can use almost any of the common insecticides such as soap spray, horticultural oil, neem, pyrethrum ect..  Really should not be that much of a problem.

Tropicaltoba

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Re: How to control a thrips infestation
« Reply #12 on: January 19, 2023, 07:24:51 PM »
Orius insidious, native bug. I get mine from natural insect control (in Canada) Iím sure there is a company in Arizona that sells them. Word of warning controlling pests with introduced predatory bugs work best in a closed environment (greenhouse) where they canít escape. It also requires a big commitment in terms of reading and understanding about pest ecology. Lastly if there is not a
Local supplier, shipping live insects gets pricey.

Tropicaltoba

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Re: How to control a thrips infestation
« Reply #13 on: January 25, 2023, 08:03:23 PM »
Here is a pic, I found one on my ugni molinae (Chilean guava) seedling today


 

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