grubs ate my lawn, what is the best remedy?

Hello, as the title suggests, I replanted about half my lawn this year and it looked better than it ever has until mid summer. At first I had some issues with some kind of fungus (possibly brown spot), and then over just a few days almost all of the new grass I had planted died off. It died so quickly there was literally a compressed mat of brown grass covering these areas. A large flock of Starlings did allot of the work for me and aerated my lawn with little holes where they went fishing for grubs. I still have some grubs around the perimeter of the dead spots. I found then when I was raking out the dead grass to replant. The dead sod was so loose that I could just sweep it up with a broom. I guess the grubs really did a number on the roots.

Anyway, I was going to replant this fall, but I want to get the grub problem under control first. Can anyone make a suggestion as to what I should use? I heard once that Bayer Merit was the only active ingredient that had been shown to work well. I have also heard the Dylox was the best fast acting ingredient. I would rather not guess about this, so if anyone can provide some information I would appreciate it.

I would also like to know if I still have time to replant after killing off the grubs. I'm in zone 6b, so I don't know if I still have time or not.

Thanks,

LMHmedchem

There are 2 basic insect groups that could be lawn grubs.
Beetles have a rather distinct life cycle, usually just one generation per year. This is what yours sounds like. There are several species of beetle, and some follow a different life cycle. Most do this:
The females lay the eggs mid to late summer. The babies may feed a bit, but not enough to cause major damage as long as the weather is mild in the fall, then they hibernate. As soon as the weather warms in the spring they start feeding again. They are much larger now and do major damage into the early to mid summer. Especially as the weather is warming and the plants need their roots to bring them the water they need. The adults emerge, breed and lay eggs in the summer.
Sudden collapse like you have seen, and the 'pull up great handfuls' is VERY typical.
Control is aimed to kill the grubs, hopefully before they get big enough to do major damage.
Check with local experts for the best pesticide. It is probably OK to apply now, if the soil is still warm, but you will probably have to deep soak it in to the soil, the grubs go deeper to overwinter.
There are natural controls such as MIlky Spore for Japanese Beetles, and other things for other species of beetles. These cannot be combined with insecticides.
For the person who absolutely will not use pesticide:
http://www.bayeradvanced.com/articles/fall-grub-control-prevention

The other major lawn pest is a group of moths. Caterpillars are the 'grubs'.
In milder climates (Florida) they are active year round, and may have more than one generation. In most places, though, the life cycle is similar to the beetles'. One generation per year, eggs laid in the summer.
Look up Sod Webworms for some of these pests.
http://ohioline.osu.edu/hyg-fact/2000/2011.html
Control is aimed at the caterpillars. Spray with Bacillus thuringiensis when the babies are really young, or stronger pesticides when the caterpillars are a bit older.

For all these pests natural methods can work really well.
There are specific predators, parasites and similar controls.
Most of these predators need a reserve of prey to be able to maintain their population, so you may have to tolerate a small 'grub' problem in the lawn, or provide the predators with other plants nearby that can host their alternate prey.
Pesticides will kill predator and prey, and usually the prey will recover faster, so the problem becomes one of constantly spraying to stay ahead of the grubs. If you can be patient, work with the predators and the natural diseases and parasites that prey on the grubs it may take time, but you could see very good control without needing pesticides.

Start with proper ID of the pest. If it is one of the grubs that are beetle larvae, make sure of the species. Find out if it is actually caterpillars (see the test in the second link).

Thanks for the informative post, I always like getting good background information.

I have attached a picture of one of the grubs. Possibly someone here can help identify it. This is definitely not a caterpillar, so I think that it is a Japanese beetle larva.
http://turf.uark.edu/turfhelp/archives/070109%20Japanese%20beetles.html

This page suggests Dylox (imidacloprid) as the best treatment for large grubs at this time of year,
http://www.uaex.edu/Other_Areas/publications/PDF/FSA-7062.pdf

I put down some Bayer Dylox and watered it in. It is supposed to be a 24-hour kill product, but it has been several days and I am still finding live grubs. It is still pretty warm and is supposed to get near 80 later this week, so I would expect the grubs to still be relatively near the surface. When I rake, the grubs seem to be just under the turf and I find then when I peel it back. I can try another dose of Dylox later this week, but I don't like the idea of saturating my lawn with a pesticide that isn't killing of what I want to get rid of.

LMHmedchem

This message was edited Sep 30, 2013 4:43 PM

The picture is of the grub from the Jenny / Daddy Long-leg's, don't know what you guy's call them over your way, the adults, as Diana said, lay there eggs in the grass, they young when hatched tunnel into the roots of the grass to be away from predators, the grubs live on LIVE grass roots hence the Starlings scratching the grass to bring the grubs to the surface. By the time the Starlings have arrived, the grubs are about ready to move to the green shoots, cast their skins and dry their wings as they are about to become adults and they in turn will mate, lay eggs and the cycle goes around again.
These grubs can kill off a whole neighbourhood of lawns when the weather is right so be aware you need to watch for the signs, a flock of Starlings on a lawn is always a bad sign as far as the lawn is concerned as they are after only one thing and it aint the bread some folks throw out to feed the birds.
There are several products on the market to treat this infestation BUT, it's finding the right time.
The garden centre should be able to help with the time to act AND your own intuition, I would think it's past the hatching time for this grub now, but next year be on guard as you have found, this can problem can happen over night IF your not watching.

Hope this helps you out a bit and you have good luck for next year.
Best Regards. WeeNel.

Sure could be Japanese Beetle, or any of several other beetles. Not a caterpillar.

When the grubs are really large (like now) it may take a stronger dose of the pesticide to kill them. I agree, I also hate to spray, I would rather try the predator/natural disease route, but when the infestation is that bad...

They may still try to come closer to the surface wen the weather is still warm. Try watering, a deep soaking, then going out an hour or two later. If the grubs are higher up, spray. Use the most concentrated dose that the label suggests.

It might help to check with your local or state extension service for suggested products and timing of applications as your taxes pay for the agency. In Texas at least, it's suggested that treatments be applied only during certain times of year when the grubs are actively feeding. In my particular case, that would be mid August to Mid September, otherwise the grubs are there and may be nibbling a bit but aren't active enough for any treatments to work reliably.
Just a thought...
Steve

Some pesticide is soaked in through the skin or breathing pores of the pest, so works whether they are eating or not. Best to apply when the pests are small, so a little bit of contact with the poison does the job, but a stronger spray when the pests are larger can also help with control.

Some pesticide is a poisoned bait, or in other ways works by the pest eating it. This sort definitely will require research for the best time to apply. In general, apply this type when the pests are very small, and when they are eating the most, so a little bit, just a bite or two is enough to kill them.

Good point to make use of the local experts.
Department of Agriculture should help. (if the offices are open!!)
Certified Nursery Person should help.
Extension service, perhaps linked to a local college that has a horticulture or agriculture program should help. Master Gardeners might help. My luck with this last group has been spotty at best.

Questions:
Proper ID of the pest.
Life cycle under local conditions.
How to monitor pest populations to best time the control efforts.
Optimum time to apply each of several possible controls.
Are any of these controls not good if combined? (Example: release predatory wasps, nematodes, or a disease that targets the pest, then spraying a pesticide is not good planning.)
Cultural controls. (less fertilizer, more careful timing of the water, optimum mowing height...)

Please keep in mind IF you use pesticides that are poisonous, there is every chance the birds will still feed on the poisoned grubs and that means this poison gets into the birds system, that could cause birth defects, soft eggs at laying time or even death of said birds.
I'm not saying that will happen BUT always best to read about those dangers first AND those pesticides are not always the cheapest way to go,
Have you not noticed a decline in the Starling population YET !!!!, once the grabs have hatched and are flightless, the birds gather on the lawn/grass to eat the grubs, BUT after a day when the grubs have dried out their wings, they take off and the problem of grub infestation is gone for this year, next year when the adults arrive back for laying of eggs, is when you should begin the spraying as the eggs will be underground till the grubs next appear in August / September depending on temp.
Hope this give a different take on the problem and some more info for you.
take good care hope next seasons lawn is green and lush.
Best Regards. WeeNel.