Merit Insecticide Question

[Peter]

I spread a 14 pound bag of Bayer Merit granulated on my yard last night, and watered the lawn afterward with between 0.25 and 0.5 inches of water to wash it in. I'm attempting to kill Japanese beetle grubs - have had a bad problem for the last tow years. I applied the Merit at a heavier rate than recommended. The recommended rate is 2.8 lbs/1000, I used 3.8 lbs/1000. My soil is clay and perculates a little slow.

Tonight we had a heavy thunderstorm and heavy rain. We got about 1 inch of rain in about 15 minutes.

My question is; did all of my Merit wash away? Should I reapply?

Thanks

Peter

[William W. Plummer]

It doesn't matter. The grubs have become Japanese beetles and are flying around now. Reapply before July 4 next year.

[Steveo]

Heh, what do you think those beetles are doing when they're not feeding?... That's right, laying eggs for the next generation.

The Merit will protect Peter's lawn from grub damage this fall and consequently next spring too.

I really doubt it has washed away, Peter. It clings to organic material real well.

[Peter]

Thanks for you reply Steveo.

Will it hurt my lawn to reapply? I *really* need to wack the grubs bad. They got me the last two years before I realized what was going on. I want the mothers dead.

Peter

"

[Steveo]

[Peter H]

Here in Ontario you are not permitted to reapply. Merit has a very long residual... and you have already admitted to applying above the recommended application rate. You should leave it alone.

Keep in mind that the application will not do anything about the existing grubs in your lawn. Merit will only prevent a new infestation. I have applied it many times and have seen it watered in, not watered in and drenched. It has still been effective in preventing a new infestation every time.

Peter H

[Peter]

Thanks Peter -

But why won't it do anything for existing grubs? I read that it kills grubs. Also, the new infestation is under way, the beetle population peaked last week and the eggs shouls start hatching grubs any day now. What I understand, now is the best time to apply Merit.

I also understand Merit is not harmful to people and pets, so overapplication doesn't have any *real* adverse effects.

Thanks

Peter

recommended

[Peter H]

Merit has a very long residual. It hangs around for about 3 months. This is why they don't permit a second application in a season here. You may as well just double the application rate initially 'cause the first application is still there.

Merit works to prevent the new, young grubs from feeding. They ingest it in very small quantities and then can't feed again which causes them to starve to death. I have found it to be virtually 100% effective even when the application is not perfect. Unfortunately the adult grubs are just too big and strong to be effected. Fortunately they will pupate into June Bugs and fly off and bother someone else in the next spring, or following one. Merit should eliminate your grub problem, but you have to be patient.

You are right when you say now is the right time to apply it.

Peter H

[Peter]

Fasinating. How does it prevent the new grubs from feeding? Why is it prohibited to reapply Merit twice in one year? What is the harm in it?

Thanks

Peter

[Steveo]

Large grubs have too much body mass/fat, they can survive the very mild active ingredient in Merit.

We use dylox to kill bad infestations of large grubs, not Merit.

As was mentioned, merit is designed as a preventative.

[Peter H]

I can't tell you the science behind it, but do know that that is how it works. You are not permitted to reapply because it has such a long residual. When I used to spray Dursban and Diazinon and had spraymix left over the next day I would just count it as water. The 1/2 life on that stuff is very short, depending upon water ph, sunlight exposure etc. Merit is different. It hangs in there.

Peter H

infestation

[Steveo]

It takes their appetite away, big grubs can live off of their body fat -much- longer than small grubs.

The small grubs starve..the big ones start eating again.

[News Man]

Thanks for your reply Peter.

But still I don't understand why it is detrimental to have too much Merit or have it reside for too long.

Thanks

application

[GentleGiant]

Peter:

Part of the answer is "HOW TO USE TO CONTROL GRUBS: "WHEN TO APPLY: Apply once anytime from May through mid-August. For best results, apply Season-Long Grub Control before grubs... hatch. Contact your County Extension Agent for the ideal dates to apply in your area."

What the label doesn't say is that if you already have any but the smallest of grubs chewing on your grass roots, the Merit stuff won't have any significant effect on them. However you can kill them with something else, such as Bayer Advanced Lawn 24 Hour Grub Control (in which the active ingredient is Dylox). If you have yellow or brown patches developing in your lawn, check to see whether there are grubs in the soil below. If there are, zap the whole lawn with Dylox, which will clear out all the active grubs. The Merit you already applied should take care of any new grubs that hatch this year.

Next year you may do better to apply the Merit product earlier in the year, before any grubs hatch - exactly when depends on your location, but there's no harm in being two or three weeks early, and a lot to lose by being two or three weeks late.

[GentleGiant]

Steveo, you are only half right. The Merit will protect Peter's lawn from grub damage this fall (to the extent that the lawn is not already damaged by grubs that had hatched and started growing before he applied the Merit).

But next spring is a different story. Even if there are no grubs in Peter's lawn this fall, there may be lots of them happily munching away on the grass roots next spring unless Peter applies Merit again in the spring before the eggs hatch. Remember it's not the grubs that lay the eggs, it's beetles, and beetles can fly in from anywhere. Merit in the grass roots this fall won't prevent beetles from depositing eggs that lie dormant in Peter's lawn until next spring.

[William W. Plummer]

[Steveo]

Hey dumbass, if he doesn't have grubs this fall, he will -NOT- have them in the spring either.

School yourself in control products next time, before you run your pie hole. -sheesh-

[Steveo]

You agree with him, William?

[William W. Plummer]

Sorry to say, but I am not sufficiently informed on Merit. But I certainly find the invective on this list objectionable.

[Steveo]

Anyone who thinks grub eggs will lay dormant until next spring is clueless.