Brown needles and silky web in hemlock

Discussion in 'Bugs and Crud' started by LWalton, Oct 6, 2017.

  1. LWalton

    LWalton New Member

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    Treated for HWA with soil injected imidacloprid earlier this year and now we're seeing this web-like substance (see pic). I won't embarrass myself with a guess.
     

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  2. JD3000

    JD3000 Well-Known Member

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    Spiders.

    But since you used Imid, look closely under magnification if need be for spider mite outbreaks.
     
  3. flyingsquirrel25

    flyingsquirrel25 Well-Known Member

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    X2 on Mite outbreak after imidicloprid treatment.
     
  4. JD3000

    JD3000 Well-Known Member

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    Might be mites.

    Hehehehee.

    I can't tell if there's stippling or not so I thought spiders first but one should look closer either way.
     
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  5. LWalton

    LWalton New Member

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    I didn't notice any stippling on the needles themselves, if that's what you're meaning. How are the the brown needle clumps produced - do the [spiders, mites, spidermites???] kill the needles (by sucking or chewing on them)? or do they just gather them (and the cause of needle browning and drop is different)?
     
  6. JD3000

    JD3000 Well-Known Member

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    I fugured the shed needles were from seasonal needle drop and they just stuck to the silk.
    Hard to say from a pic but there could be some other critter I'm not familiar with or some minor foliar fungal issue.
     
  7. LWalton

    LWalton New Member

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    Is mite damage a serious enough problem to warrant treatment? Perhaps it depends on the degree to which there's mite damage. If it is affecting >50% of the branches, what treatment do you guys use?
     
  8. JD3000

    JD3000 Well-Known Member

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    Abamectin is inexpensive but nasty stuff.

    Floramite and Hexygon have low toxicity and minimal impact on beneficials.

    Forbid works wonderfully but is expensive.

    Soaps, oils, neem oil.
     
  9. jed1124

    jed1124 Member

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    Horticultural oil at 2% will take care of your mites and adelgid. What rate did you apply the imidacloprid at?
    Keep in mind yearly applications of imidacloprid are not necessary to control adelgid. I've seen mite outbreaks from yearly apps.
    1 app at .2 oz. per inch of dbh should give you at least 5 years of control for adelgid.
     

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