Japanese beetle grubs

Discussion in 'Pesticide & Herbicide Application' started by Yatt, May 9, 2013.

  1. Yatt

    Yatt LawnSite Member
    Messages: 203

    This week I had bare and dead spots in several clients lawns that I attributed to the drought last year. (these same areas had severe mole activity too)

    When the Reinders rep brought me the balance of the fertilizer shipment I had him take a look and he attributed it to grubs from Japanese beetles. Up until recently these were never an issue.

    He suggested a Merit based fertilizer to be applied in June. From what I understand you need to get them at the first instar stage.

    So what everybody use, straight Merit (imadacloprid), fertilizer with Merit or can imadcloprid be added to a broad leaf treatment and sprayed at the same time?

  2. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,794

    Cold where you are. I think about the first week of July is better.

    HOWEVER, BE PROFESSIONAL--get your license; learn to recognize grubs for yourself. Dig up some dirt and find the grubs. Find out what moles actually eat.
    You would be crazy to treat for grubs because he wanted to sell you a few thousand dollars of Merit.
    More likely you are correct--drought damage.
  3. DA Quality Lawn & YS

    DA Quality Lawn & YS LawnSite Fanatic
    Messages: 9,288

    Riggle is right, highly doubtful it is grubs this far north. Over my 6 years in biz, I have checked for grubs many times but never found any where I thought they may be. Hence, I have not once applied any grub treatment.
    And you are as far north as we are.
  4. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    I've seen June Bug grubs when ploughing up a pasture, but one could never notice it from above... I too have never seen grub damage to lawns... the only thing ever noticed was the skunks going through and ripping up the lawn to get at the grubs...

    Junebugs must feed so deeply in the turf that their activities do not necessarily kill the turf above...
  5. caseysmowing

    caseysmowing LawnSite Silver Member
    Messages: 2,137

    I actually had my first lawn that had grin damage from what I could tell. I have had other lawns that skunks have torn up. Either way you would want to get rid of them. My lawn has them really bad along with moles. One day I'll have the money to get around to it and time.
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  6. Yatt

    Yatt LawnSite Member
    Messages: 203

    I am licensced.

    I am not about to just treat because a salesman suggested something. I intend to dig up some sod and see for myself. It has been extremely cold this year and things are way behind schedule. I have not even mowed my own yard yet.
  7. Yatt

    Yatt LawnSite Member
    Messages: 203

    Well the one client has japanese beetles traps out. Yes I understand that the pherones used probably draw more than they kill and exacerbate the situation. However he catches several gallons of them in the traps and the traps have to be emptied every couple day due to the bags being full.
    So how many japanese beetles are in a gallon? I would say quite a few and that indicates a problem.

    The area I service is semi rural with very large lawns surrounded by woods. From what I understand the japanese beetle life cycle centers around the adulsts laying 4-5 eggs at a time in the sod, the instar molts 3 times at which time it goes deep and comes out in the spring to start the process over. With density of the pest adults, they have to be in the sod and not in the woods where there are no grass roots to feed on.
  8. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,794

    Life cycle sounds about right. Around here, grubs feed for a short time in the spring. Then pupate. Emerge as adults. Mate. Lay eggs. New grubs emerge. Main damage occurs in October.
    Japanese beetles emerge around June 15. Best time to treat, I have been told is about July 4th, --about when the eggs hatch. If using Acelepryn, treat a few days earlier as it is a bit slow to uptake--yet long lasting.
  9. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    I believe Riggle has it right as far as timing... I find it hard to believe that the grubs woke up under the snow and started eating roots a couple of weeks ago, already...
  10. phasthound

    phasthound LawnSite Fanatic
    Messages: 5,159

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