A Gardeners Forum Forums Gardening Reference Gardening in 2006 Grubs questions

I get a ton of grubs in my yard.. brown spots lots in the soil when I dig..I use Grub x on them.
I was Just wondering what is the best way to keep them from eating my grass.. I have heard that punching holes is suppose to help..
what do these larve turn into?

Beetles!
...like the European chafer or Japanese beetle.
(I don't like beetles!)

Grosss :p I hate hate hate beetles.. list of things to buy MORE GRUB-X...
Eat my trees and such... Is there a better way of getting rid of them???
Do they eat plants too?

Grub-Ex should work fine, as long as it is watered in with in 3 days of the application. The only bad thing about it is that while Grub-Ex protects for the entire season, it takes 2 to 3 weeks to become active in the plant. There are 2 different types of grub insecticides on the market. One is a preventative, like Grub-Ex or Merit, and the other is a contact killer. The contact killers work faster but only last for a couple of weeks at best. Personally I like using the preventative application because the curative type of insecticde is pretty much non selective and will take out pretty much any insect that it comes in contact with, including a host of good ones that are beneficial to your lawn. The preventers actually make the grass inedible to the insects there for it reduces the damage to the good insects as they won't be the ones eating your lawn.

Punching holes will not do any additional good, unless you happen to have a thatch layer "from Hades". As long as it is watered in it should work quite well.

Thanks Mike... that cleared it up for me... Do grubs eat flower roots as well?

Yes they will but not to the extent where treating your flower beds will do any good. flower roots are much tougher then the grass roots, so they can only work at the very fresh tips, which will not hurt the plant.

Excellent !! It was bugging me.. knowing I just planted a bunch and would be bummed if they killed the flowers too!! Thanks a bunch!!

Timing is everything with grub control. Right now is too early to treat unless you want to make an additional application in July. Wait til Mid to late May. Do not believe the whole "season long" control hype that is touted. There are many variables to consider. Under the best conditions Imidacloprid(Merit) has a soil half-life of six months. Realistically, though, it is more like 60 days and needs to be watered in to be translocated in the turf plants to become effective. Translocation only takes a few days. Not weeks. Right now grubs are in the very early stages of moving to the surface to feed. If you wait a few weeks you will have a better chance of controlling TWO generations of grubs. The late stage larvae that will feed and emerge as beetles in June and the larvae that will hatch and feed voraciously in July/Aug. Most turf damage is done by the second generation in late summer.

Also, imidacloprid is toxic to earthworms and birds. Just so you know.

we do apply in may.. the big thing for me is do you have to do it every year.I do every year.. I Just can't figure out where all those grubs bome from.. do they ever go anywhere else but my yard??

Applying the preventative in May should be fine. You can put it down as soon as the grass starts actively growing.
As far as where they come from? In your area, they would more then likely be Japanese Beetle larva. As the beetles fly around eating every ones plants and clogging up every ones swimming pool filters they are attracted to nice lush green lawns. They mate then fly down and lay their eggs. The eggs hatch into grubs and they hang out for a few weeks and wreck havoc on your lawn. Then the grubs burrow down deep, and winter over. Late the next spring they will work their way back up to the surface, and start pigging out on your lawn again. After a while they morph into the beetle stage and it all starts over again.
Out here in the mid west we mostly have the European Chafer, it is not as damaging as the jap beetle grubs but they do their fair share of damage as well.

Maybe I should let the lawn go
Interesting to know thanks Mike ..
I guess I will have to live with the ugly buggers for a few more weeks .. Stupid mighty morphin beetle bugs!

japanese beetle larvae need to be treated with milky spore. and it takes a couple of years to become fully affective.

the grubex stuff is for the rest of the beetle larvae.

What is milky spore?

Grubex also kills japanese beetle larvae. Milky spore is a natural bacteria used as an organic method of control. And not a very effective one IMO.

Milky spore is a "natural" alternative that has been pushed by environmentalists for years.
It is a fungi which supposedly builds up in the ground that makes the ground uninhabitable by the grubs. In essence it sounds like a very good idea, but there are many things which can make this treatment not work. Too sandy of a soil, high acidity, too dry, too wet, etc... Even if it does work, it still takes years for it to build up to the point of having any effect on the grubs.
Another reason which I am very leery about that is that playing around with biologic control methods can be much more dangerous in the long run, then using chemicals. There are reasons why some things are naturally occurring in certain areas, and playing around with them can cause long lasting negative results. Look at what happened with the Asian Lady Bug. It was brought into an area to help farmers fend off aphids from their crops. It sounded like a great idea at the time, but a few years later we realized the big mistake that was made. The lady bug population exploded and what we brought in as a tool to control the pest actually became the pest.

Hey John! We agreed!

I'm shocked .. finally agreed..
I will stick with the grub-x thanks boys!

Another biological control introduced several years ago is a type of nematode (Heterorhabditis bacteriophora) ... it's only supposed to take 2 to 4 days for complete control (a.k.a. death) of the grubs.

I -- thankfully -- haven't had any grub problems to speak of, but am curious if anyone has heard anyhting about these nematodes ... ???

I do agree that using biological controls can be fraught with unknowns, but I'm not sold on the whole chemical bit either.

A study at Rutgers University found that heterorhabditis bacteriophora does work against Japanese beetle grubs, but has little to no effect on the European chafer or oriental beetles larva. Also while beneficial nematodes can work, they are not for every soil or climate type. It would be best to check at your local ext. office to see if they can be used in your area.
They can also be pretty expensive upwards of $30.00 to treat 3000 sq feet

I used GrubX when I was supposed to but I still got an infestation of Japanese beetles! My backyard is 10,000 sq.ft. and I treated both front and back. About a month after I treated the areas, I called Scott's to see if I needed to treat it again...they said no.

If the grubs were killed, why did I get so many beetles? What do I need to do now? Do I need to treat the yard again? My lawn is beautiful but my roses are being destroyed!

Help!!

While GrubX targets the white grub it is not an effective control measure against the beetles themseleves.The beetles fly in from other areas. They are attracted to large green sunlit lush areas. In other words "lawns".
Once the larva hatch into beetles they can fly for miles in search of food and mates.
GrubX and similar products will only work if the application is watered in within a few days of the application.
The same ingredient in GrubX is also available to treat your roses with under the brand name of MERIT it will make the roses inedible to the insects. Another possibility would be to put some beetle traps around the perimeter of your property. DO NOT PUT THEM NEAR YOUR plants!!! they attract the bugs by color and with a scent. They work very well, but you want to try to draw them away from your plants, not bring them closer.

Thanks Doc! That's excellent information. I did setup beetle traps but I think I had them too close to the plants. That's what I get for reading the instructions wrong.

CeeView

You're in CT. When did you apply the product?

Yes...I'm in CT and if you're asking about the Grubx, it was applied during the time frame it was supposed to be put down. The did a number on my roses...fortunately, they seem to have died down.

I wanted to apply a second dose during that time, but Scott's said I didn't have to. Do I need to put down Grubx again before the winter?

One application should be enough for a season.
Some folks like to do it in the fall, and say they have better results, I happen to like doing it during the spring once what ever plant you are treating starts actively growing. The beetles should be leaving by now and their young should start showing up wrecking havoc in lawns as grubs, so as long as you applied the product right, your lawn should be protected by this point.