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lmatt_gw

Pepper plant insecticide question

lmatt
9 years ago

Is resmethrin/tetramethrin insecticide safe for my indoor pepper plants? They seem to be derived from the pyrethrum insecticides, but I'm not sure. Will it burn or kill the plants?

Comments (11)

  • woohooman San Diego CA zone 10a
    9 years ago

    Before we get into this particular pesticide, what pest are you trying to control? I can't think of any INDOOR pepper pests that would NEED a pyrethrin/pyrethroid based pesticide.

    Kevin

  • lmatt
    Original Author
    9 years ago

    Sorry for not clarifying. I'm having a infestation of fungus gnats around my pepper plants. I tried using insecticidal soap, but it seemed to have a phytotoxic effect on my plants. I was thinking maybe a pyrethrin based insecticide would be safer.

  • woohooman San Diego CA zone 10a
    9 years ago

    Yes. Insecticidal soap can be harmful if applied and then brightness or warmth is intense. Not sure how that would apply in your case but if it happened, it happened.

    For future reference, never apply ANY pesticide when temps are >80F or the sum of the temp and humidity is >140. For this reason (with insecticidal soap), I apply in the evening and rinse off in the morning. Since it's a contact killer, there's no reason to leave it on the plant.

    Back to the fungus gnats -- not sure if either take care of them(you can ask in the garden clinic forum). But, here are some things you may want to try that are much less stressful.

    1) Usually, fungus gnats are a byproduct from overwatering. So, don't overwater. Bottom watering helps (particularly with seedlings), but also let soil become completely dry between waterings. Also, setting up a small fan helps dry out the top layer of soil where gnat larvae are.

    2) Sprinkle cinnamon around. Just one of those natural deterrents that nature gives us.

    3) Every 2 weeks, water with 1 part hydrogen peroxide(3%) to 4 parts water. This really keeps the damping off fungus at bay.

    4) Last but not least... mosquito dunks. Bacillus thuringiensis Israelensis variant. NOT the K (kurstaki) variant -- which is used for caterpillars). A bacteria that attacks the larvae.

    5) Neem oil. This one I figured out myself. It kills soft bodied insects like fungus gnats but also doubles as a fungicide.

    Fungus gnats aren't really a pest problem past the seedling stage. Normally one can control them with cultural practices which brings us back to the whole overwatering/air circulation stuff i mentioned above.

    Kevin

  • northeast_chileman
    9 years ago

    Thank you Kevin!

    It's amazing how much I learn here...

  • seysonn
    9 years ago

    I agree with you, nc

    We have some knowledgeable people around here like Kevin, Josh, Bruce, Dennis, Ronny,SmokeM, ... and some others.
    I keep learning about peppers here everyday.

    On Fungus Gnat, it has been an issue with my seedlings only . At Kevin's recommendation I used mosquito dunks and it resolved my problem. I also tried cinnamon powder and camomile tea. But out side I have not encountered any pest or disease issues with my pepper plants other than earwigs and slugs. I have to be more diligent on those the next season.

    Seysonn

  • esox07 (4b) Wisconsin
    9 years ago

    Thanks Seysonn. I agree with Kevin as well. When I had the fungus gnat problem, I solved it with several waterings using a 1 part Hydro Peroxide to 4 parts water solution. They are typically a problem for me when I am growing my seedlings in the winter. The hydro peroxide solution will kill or repel the gnat adults and kill the eggs and larva already in the soil. With repeated applications, it continues to kill the larva and eggs until they are 100% exterminated and there wont be any left to come back after the hydro peroxide wears off. With only one application, you will get rid of them for a little while but the adults will just stay away for a few days and then return when you water again and the old application of hydro peroxide wears off. You need to kill off all three generations of the little buggers. And occassional applications there after will help keep the fungus gnats away. It is a much more natural remedy and is harmless to humans and others.
    But keep in mind that the fungus gnats need damp soil, so letting it dry out almost completely between waterings will help keep them away in the first place.

    The fungus gnats typically are typically more of a nuisance than a real threat to your plants. The larva will feed on the tiny delicate roots of plants which can harm the plant if the infestation is really bad.

  • ronnyb123
    9 years ago

    For me, I use diatomaceous earth in the pots to kill the adults. It seems to work well and will destroy the population in no time. It shreds them up I hear. I also add the sticky yellow paper strips around the plants to catch the flying adults that seem to still come in from outside. The only bad thing about powder is you must add power again when you water since it cakes rather quicky, but if done correctly you may only have to do it once or twice. It also wont harm leaves or fruit if put on them too. For the maggots in the soil, mosquito dunks or a brew of pepermint and chamole tea, seeped for a few days worked for me.

    Less watering is best

  • woohooman San Diego CA zone 10a
    9 years ago

    Watch it with the DE, Ronny. Though it's considered an organic pesticide, it's very broad spectrum-- meaning that any INSECT(or gastropod) that crawls over it is killed.

    So, let's say you have some ladydug or lacewing larvae(beneficials, but flightless) that want to wander out of a plant and into another one, they're doomed also. :(.

    For the sake of the OP's case though, indoor usage shouldn't be a problem.

    On a side note--- loving it going out and checking my plants in mid Autumn and seeing quite a few ladybug larvae and even lacewings. GO BIOCONTROL! And Chargers! ;)

    Kevin

  • ronnyb123
    9 years ago

    That is true. It does kill any walking insect (good or bad) which is why I usually only use it in extreme cases. That would be your green house is overrun and you just want to throw a bomb in there, it is that frustrating. Outside, it is useless, as there are too many variants. It does work great though.

    Never seen lacewing bugs and ladybugs are hard to come by. Even bees hardly ever show. It could be no flowers and a stone backyard does it. Hummmmm.

  • seysonn
    9 years ago

    On the topic: This past season I had Earwig problem, eating my pepper s leaves and I suspect them made holes in some pods.

    What is the best way to fight them (next year) ?
    I have heard about traps, oil, etc. I need an easy way. to eradicate them. I get no Lady Bugs or Lacewing here.
    But I do get bees that are only interested in the flowers.

    Seysonn

  • woohooman San Diego CA zone 10a
    9 years ago

    Seysonn: I've never found earwigs to be TOO much of a problem once the seedlings get some foliage. I've tried the oil and soy sauce traps and though they attract a FEW earwigs, they really attract pill bugs more than anything else. Sluggo PLUS is supposed to not only take care of slugs/snails, but also earwigs. Click on the link. Looks like i made the wrong traps

    Ronny: Ahh. Yeah. I can see it being appropriate in a greenhouse. LOL in regards to the stone backyard and no flowers. Yep. Gotta have the beneficial flowers/herbs/veggies that attract beneficials. They'll come around without flowers but once they're done eating, they'll move on. Having flowers gives them nectar to feed on(and reproduce) when the bad guys populations have diminished.

    Kevin

    Here is a link that might be useful: earwigs

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