I picked at least 20 of these containers, each full of grubs, out of just a small area of my soil. :(

I have not used nematodes for grubs, but we had remarkable success using a nematode product for fleas.

It's a shame you no longer have wild turkeys about- what a smorgasbord!

Virginia

I agree. Maybe the drought brought the coyotes and mountain lions down lower this summer and they ate the turkeys. :(

The ecosystem in my yard is just all messed up now!

Well, I guess I might as well try the predator nematodes. I do NOT want this many grubs or this many beetles. And if they help with fleas and other insects too... Bonus.

Man. I'm gonna have to buy a bunch of nematodes for this many grubs in this large of a yard! It's probabaly going to help the whole neighborhood. My neighbors should be thanking me!

I am planning to use it against rose midge next spring. I posted a thread about 3-4 weeks ago, no one was interested. Pretty happy to see your thread! It's getting cold here up north, they need temp to be above 45F, so I will treat my lawn and garden next spring with Predator Nematodes.

I just dug a little around my roses and there are a few. Not 50 every square foot like near my island snapdragons, but enough to make me unhappy. Now I know why my island snapdragons were dying. I really hope the predator nematodes work.

Too much organic material on and in the soil for a med type climate. That has always been my opinion about mulching and excessive composting but I know many will disagree as this is a controversial subject. Solarizing works wonders but of course one cannot do that on a planted area.

An interesting comment, Nik. Without mulching, for which I use the leaves from an African tree which are large and soft plus the spent rose blooms and kitchen waste, my roses wouldn't survive with the intense radiation from the sun and the poor soil of decomposed granite. Fortunately I have almost no grubs. The mulch keeps the soil cooler which lessens the amount of water I have to use.

In my undocumented opinion, the effects of mulch on water loss due to sun radiation are overestimated unless we're talking about very superficial rooting plants.

Nik and Ingrid you both make great points. In my particular case though, I personally think it has more to do with the wild turkeys being absent and the family of raccoons we removed from under the house.

I mulch... But I don't find I need to compost in my particular yard. There is a lot of organic material from several established neighbor trees nearby.

We solarized and smothered our lawn years ago. It worked great. No grub, beetle or other infestation problems until now. :(

And let's not forget these darn grubs (and beetles) could have moved in from a neighbors yard.... With lawn.

Probabaly less about the mulch and more about the total impact of the entire ecosystem going on in my neighborhood right now. Although, mulch and compost may be a small part of that. Just my humble opinion though.

Regardless, back to the question... Anyone have experience or tips with predator nematodes for grubs? Anything I should know?

At this point I'm pretty set on that direction. Going to call Natures Control (out of Washington or Oregon I think) this afternoon.

Professor Malcolm would be the right person to ask and get an answer back fast.

Just bought 6 million double death predator nematodes. Supposed to be enough to treat 18,000 square feet, which I believe is a little less than a half acre. The next step up is 24 million so I thought I would start with 6 million before going to the super duper size. Hopefully this does the trick before they munch on more than the island snapdragons.

Icky!!! I had some grubs like you have in your soil but mine were in a large container, I found them after doing some investigation when I noticed the plants were doing poorly. I think in my case the grubs came in on some wood chip mulch. I did end up using predictor nematodes and they seemed to take care of the problem. The grubs seem to prefer the root areas of plants--which they eat. I remember one of the instructions said to apply in the evening since the nematodes will die in sunlight and they need time to move down into the soil.

I hope your nematodes arrive hungry! Please post an update after you feel that you can assess the effects.

Virginia

Are those nematodes wide range or species specific? If they are species specific are you sure you have the right nematodes or grubs? If they are wide range keep in mind that beetle larvae are pretty difficult to tell apart and not all grubs (and adults beetles) pose equal danger to roots and vegetation. Some grubs are pretty benign prefering to feed on dead organic material rather than living roots and many beetles are not much more than a minor nuisance. Plus, of course, not all soil dwelling insects are pests..

Thank you so much for the info Rhodes. I'm glad to hear they worked for you!

Summersrhythym I'm honestly not sure how to ask a question to one person on gardenweb. :/ But thank you for the idea.

Good points Nik.

These grubs were munching on my island snapdragon bush roots. So they like living flower roots. Buggers.

Even so, I personally don't really want to use a product like Bayer unless absolutely necessary. I prefer a more organic/permaculture route when possible. I much prefer trying predator nematodes.

The double death predator nematodes I bought from Natures Control in Oregon include: (Steinernema carpocapsae & Heterorhabditis heliothedis).

Here's a link to info about them in case anyone is interested: http://www.naturescontrol.com/predatornematodes.html

According to Natures Control, "They attack and kill more than 250 different insects, including Fleas, Thrips, Fungus Gnats, even insects as large as Cutworms." They also have been raised on a diet of live bugs so they supposedly are better at hunting for their food.

I will update once they arrive and I have a chance to evaluate.

All my neighbors have lawns that are stressed because of the droughts. Trees are stressed too. I also live in a semi rural area. The hills and trees around us are completely stressed because of the droughts. If the wild turkeys that are usually around here got eaten this summer, pest like grubs could end up being an annual problem since the balance would be different. If the predator nematodes work i might just get them annually from this point forward.

The predator nematodes from Natures Control came nicely packaged with a cold pack, the name of the person who packed them (thanks Doug!) and lots of literature on "hired bugs."

It is supposed to be in the 90s over the weekend so I'm contemplating waiting until Sunday night to let them loose in my yard, but I might just do it tonight to be done with it. They're in the fridge waiting for me to make up my mind.

I will update again after I see the effects of these 6 million little predators.

I went ahead and just let the predator nematodes loose tonight. I followed the directions for the most part. Here's a couple tips from my experience. It was really easy. Just open the ziplock bag, put the sponge of nematodes in a watering can (that is at least a gallon), rinse it by spraying it with the hose (while inside the watering can), then water the plants and the ground with the nematode water.

The directions recommend rinsing the nematode sponge in a gallon of water, then diluting further if you want. My watering can is 2 gallons, so I just used that. But, I wanted to use every last nematode so I rinsed the same sponge again for another 2 gallons, then reapplied it over the same area. I also rinsed the plastic bag into the water. Then I also buried the sponge and the bag in the ground when I was done with it and sprayed it with more water. Again... I wanted *every*last*one.

The thing is the directions say to water the ground before and after ... to create a humid environment and to water them in 3 inches after you apply them.

If you live in an area that has humidity or moist soil or if you have a sprinkler system, that's probably not a problem.

If you live where I do, and have drip irrigation, that takes days of planning.

The rain probabaly isn't going to wet the soil 3 inches until April.

And the areas that aren't touched by the drip irrigation are bone dry. But still have the damn grubs.

So I was stuck using the hose. With my soil, that meant preparing by wetting down the soil every day for the past few days since I ordered the grubs.

I decided to do it tonight because it's going to be hot tomorrow and possibly evaporate all the watering I have been doing to get the soil moist.

So.... if you can, make it easy on yourself and apply predator nematodes after at least 5-10 GOOD DEEP rains. If you live in an area where it hardly ever rains, or have an acute, immediate problem like me, just prepare to spend a lot of time and money watering them in to get them down 3 inches.

I'm going to check the effects and reapply in a couple weeks like the company recommends. I will post an update. :)

It's only been four days, but the literature says juvenile predator nematodes kill their hosts within 2-4 days, then move on to their next host... so I checked the soil to see if I could find any little grub carcasses to see if the nematodes are doing their job. I found a couple. Too early to tell though.

But ... The more I looked around.. I also found SO MANY nasty little live grubs. Sorry this is graphic, but so is nature. I tried to squish as many as I could between cobblestones before getting disheartened. I really hope the predator nematodes go to town. The good thing is the grubs all seem to be focused on the area where the island snapdragons were (I moved them). There are some near my roses, but not as many. Same with my azalea and rhodies. There are hardly any near my nepeta or thyme. Whatever they are must really like island snapdragon.

The nepeta and thyme may not be a smell/taste that they like. Good to know for future companion plantings near roses. That's what I typically plant near roses because I just like it ... but now I have even more reason.

Do you utilize silicates in your arsenal of weapons against plant feeding insects?

http://gradworks.umi.com/10/12/10124291.html 

No I don't... haven't heard of this... ? The link isn't working.

I usually don't have pests problems and don't use anything to fight insects ... except the hose when aphids come around.

I am so upset about this darn grubs. And I absolutely hate the idea of them growing up and becoming a beetle infestation.

Sorry, it does not work for me now also. Hopefully, this one will work:

http://search.proquest.com/docview/1807631823

"Preliminary studies by our lab found a reduction in CLM feeding damage following treatment with soluble silicon. To expand on these results we sought to determine CLM oviposition preference, host acceptance, and preference for host volatiles. CLM adults were given a choice between a soluble silicon treated plant and a control. Adults were allowed to oviposit, then citrus leaves were inspected for eggs. CLM adults were also offered a dual choice in a glass Y-tube olfactometer. CLM adult females laid significantly fewer eggs on plants treated with soluble silicon. The evidence strongly suggests a silicate-induced change in the tactile or chemical profile of the leaf occurred. We also aimed to examine whether soluble silicate fertilizer could affect CLM population growth. To that end we sought to determine CLM larval feeding performance, quantify differences in rate of development and mortality of the larvae and pupae. The development of CLM from larvae to adult was observed and compared on soluble silicon fertilized plants vs. controls. We calculated net replacement rate (R0) of CLM. CLM on soluble silicon fertilized plants had significantly lower survivorship than CLM on controls. The lower survivorship of CLM on soluble silicon plants suggests the possibility of induced plant defensive chemicals in the plants."

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I assumed that you were concerned that the grubs would turn into beetles and they would eat your roses.

"004 Root Application of Potassium Silicate Reduce Feeding Damage to Sargent Crabapple Leaf Tissues by Adult Japanese Beetles" (see link below)
There also is a 2001 report by A. M. Shirzai and F. D. Miller in the following:

Shirazi A.M. and F.D. Miller 2001. Root application of potassium silicate reduce feeding damage to Sargent crabapple leaf tissues by adult Japanese beetles. p. 390. Poster Abstracts. In L.E. Datnoff et al., (eds.) Studies in Plant Science: Silicon in Agriculture Vol. 8, Elsevier Science. B.V., Amsterdam.

Here is a link that might be useful: Shirazi and Miller link HortScience June 1999 vol. 34 no. 3 441

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http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-04882012000100005

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-http://onlinelibrary.wiley.com/doi/10.1002/ps.1302/abstract?userIsAuthenticated=false&deniedAccessCustomisedMessage=

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Hmmm. I have citrus trees and citrus leaf miner is a problem here so this is interesting, if only for that reason! I don't think northern California has Japanese beetles yet, so these grubs are something else... but whatever they are I don't want that many beetles (or that many grubs) in my yard! Thanks for this. I had never heard of silicates before.

Henry, would this be a product like Dyna Grow Pro Tekt?

Cori maybe the leftover grubs are beneficial ones that were unaffected by your nematodes? The JB were horrible for me this year!

Dingo... We will see in a few weeks after a second application. I don't think I'm quite that lucky.

This morning I read this thread with some interest, then went out to do garden cleanup. This involved spreading old hay, from bales that have been sitting around for a year or two. I noticed that, very unusually, the hay had no grubs in it. We have abundant beetles, abundant grubs. Then I remembered the infuriating mystery animal--I think it's a badger--that digs up our freshly amended holes in search of bugs. It trashes the garden in the most maddening manner--though usually only freshly prepared ground--and for the first time it occurred to me that it might be making a positive contribution to our gardening by eating said grubs.

Yup. I used to curse the raccoons and turkeys when I saw their handiwork. But now I know better and I appreciate them immensely.

I'm still glad I had the family of raccoons removed from under the house tho. They're so mean.

Cori Ann,

I can report that canopy spraying with a silicon based product helps with the citrus leaf miner. The problem is that spraying must be timed to coincide with the new flushes before the insect has had a chance to lay its eggs. Easier said than done in a climate where citrus flushes are almost continous and even more difficult in a garden with a variety of different citrus tree. Additionally such use is quite new to know if too much spraying has any adverse effects with regards to tree health and growth. I have no clue if root drenching has any effect and if it is viable or economical to perform.

Talking of racoons..

Racoon steals guy's phone while being videoed (is this a word?) and takes off..

Well it's been about 2 weeks and although the area that I totally saturated with 6 million predator nematodes is better... there still really aren't enough dead grubs for me to feel good about how they're working. I also noticed just about 10 yards away the grubs have moved in and they're now eating my azalea roots. Not cool.

I am going to Bayer. I haven't given up on the predator nematodes for the future, but I think in this instance I'm going to use the heavy duty grub killler.

Maybe it's hard for the predator nematodes to work in drought conditions. Which would suck since that's when the grubs seem to really go to town. I would say they're still worth a try, especially if you live in an area that gets a little more water and a little less sun.

But this is what I still have in the permanent drought soil of NorCal. They're going down today. Bayer style.

Yuck those photos bring back memories from the fall of the grub massacre I committed with my gloved hands. So gross.

But... I put out a new batch of predator nematodes a week or two ago and WOW they went to town! I found some bug carcasses this past weekend in the soil, and it's pretty obvious when it is from the predator nematodes feeding on them... they look like little mummified bugs with all the life sucked out of them.

Here's what is different this time compared to the first time (in order of what I think made the biggest difference... but there's no science to it, just my mind)

Water. The soil is WET way deep down from all the rain we have had in Northern California.

Kept them in the fridge. I did that so I could prune the roses and spray with horticultural oil. I kept them in the fridge for about 4-6 weeks, re-wetting them if needed. Last time I put them in the soil right away. I think they went to sleep in the fridge and woke up HUNGRY.

Different time of year. It was still so damn hot in the fall here. I mean most days it was above 90 or 100! And in the fall there were SOOOoooo many grubs. Too many for them to eat probably. And they couldn't move around all that well since the soil was so dry, even though I tried my best to water them in. There may not be as many grubs now since I squished them by the 100s, then poisoned them (sorry earth).... but there's still a few and there's other pests for them to eat in there. I just think that this time of the year has a better climate for them to do their thing.

Hopefully the grub infestation from last year was a one time thing and isn't going to happen again next fall!

If you live somewhere really hot and super dry and are thinking of using predator nematodes, you may want to do it in the winter/spring (or whatever season it rains and is warm enough) so you don't just waste your money on nematode jerky for your soil. :)

I will give it a try this spring to fight against midge, it would be nice to use less chemicals, I want to get my herb garden back. I put so many roses in the herb garden, I couldn't use any herbs after the treatments for midge.

Summers I'm not 100% convinced that they all get rinsed out of the sponge into the water (you will see what I mean when you get them).... so I rinse them and water them in as directed, but then I also bury the applicator sponge in the wet soil. You may want to try that too. ;)

Your grubs look just like mine. I used that same product, two years in a row about 3&4 years ago and noticed no difference in the grub population during either of those seasons, and no difference since then. Under the microscope there were plenty of active nematodes in what they gave me. Maybe my climate doesn't support those nematodes? Or are they just not effective?

You didn't see any of the little carcasses? Did you call the supplier to find out? What type of predator nematodes were they?

For me, I believe it made the biggest difference to use them in wet soil, instead of the dry soil of fall, but my soil is sooooo dry usually during the year because we don't (normally) have much rain and it stays so hot here.

Just curious, how do you know there were active nematodes visible under a microscope?

I have a pack of them in my fridge waiting this weekend to come, just
had good rain again, so yes, that will be easier to keep them alive. By
the way, there are 3 different types of nematodes and they are hunting
for their own food. Oh, and seems like they depend on the soil type,
whether it's clay, sand...I bought them from http://www.arbico-organics.com/category/nematode-selection-chart. 

That is a great page of info Natasha! Arbico did a good job of organizing all the info into tables and making it easy to understand. And Arbico is right there in AZ so I bet since they're local to you they will be able to recommend the best type(s).

My double death nematodes from Nature's Control in Oregon are the Sc and Hb types. Good for the application needs I had and the soil here.

I'm tempted to get the Sf types from Arbico too just to cover all the bases... maybe for my fruits and my citrus trees. Thanks for that link!

You are welcome, Cori Ann, I liked their web-site too. I visited them on President's day. They are couple hours of driving from me but I decided that it would worth it since nematodes shall be kept cool and was not sure about delivery trucks anyway... I wanted to buy all 3 kinds first to get rid of everything! But then changed my mind - I really need to get rid of grubs. Maybe next spring I will go full load :) their nematodes come with a powder, haven't looked inside of my pack though... And I agree with you that spring is the best time to apply them in our arid conditions, I've being doing a lot of digging lately and my clay is damp as far as I went.

If you get a chance, please post a quick update on how your application goes. I'm really curious about it since it seems a little different from Natures Control. :)

No, I didn't see any grub carcasses when digging. Just live plump ones. There were some yellow ones, but when I looked on the web, they are just a different species. The number of grubs per area of soil really didn't seem to change. Under the microscope, they were definitely microscopic worm-like creatures, wiggling around. They looked just like the nematode images on-line.