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View Full Version : Merit drench for Jap Beetles


Lbilawncare
01-26-2008, 02:50 AM
Does anyone use Merit as a soil drench japanese beetle "preventative"? If so, is it worth the cost and what rate did you use? I realize the beetles will still munch the leaves a bit, but I'm comparing the effectiveness to spraying after activity has begun. Thanks !

Whitey4
01-26-2008, 12:54 PM
Geeze, I hate using the word "drench". Too many home owners did just that and now Merit is restricted here... it showed up in some wells. I don't think any chemical should be used as a "preventative". Using Merit should be based on a grub count in a sq foot of turf.

Besides that, the larvae that is about to come up through the frost line soon has overwintered. These mature larvae are much harder to kill than newly hatched ones are. If they are Japanese beetles, and not another type, milky spore will wipe them out with a spring app. Using Merit on them might only make the eggs they lay this summer more pesticide resistant. The best time for treatment is after they laid their eggs, and the immature larvae hatch.

When beetles are in their adult stage and flying, they may not have even come up from the turf you want to treat. Japanese beetles will fly considerable distances for their favorite vegitation. Since the Europen Chaffer and Oriental beetles don't eat in the adult, winged instar, they are likely hatched from closeby. They are only flying to mate and lay eggs.

While milky spore is expensive, it is very safe compared to using a chemical application in the spring, when rain will leach it much faster through the soil. And Jap. beetles can't develop a resistance to it. It is extremely effective, but only on Japanese beetles, no other type.

You would still have to treat their favorite vegitation like rose bushes and rasberry plants, and trap baits placed well away from those targets of the beetle work well in reducing the entire area's population. Get the adults before they lay. Problem with the hormone based bags is that they have to be emptied frequently. It's sort of nasty, and many home owners aren't willing to stay on top of it.

LIBERTYLANDSCAPING
01-26-2008, 01:58 PM
Soil drench IS a great way to control jap. beatle, as well as other damage on ornamental (scale, bagworms, etc.) The other upside to it is you don't have the problem with killing off insects that prey on Mites, like you do with a foliar spray.

Using bags is a "garden center" control mentality that is scoffed at by most land grant universities. They will tell you you may well attract many more beatles onto your properties with these, than would normally be there (as they will fly for many miles) Milky Spore is expensive, hocus pokus crap.

Russ
01-26-2008, 02:13 PM
baits placed well away from those targets of the beetle work well in reducing the entire area's population. Get the adults before they lay. Problem with the hormone based bags is that they have to be emptied frequently. It's sort of nasty, and many home owners aren't willing to stay on top of it.

NEVER EVER USE PHEROMONE TRAPS Unless you are pi$$ed at everyone in the neighborhood. It is well documented that they are not capable of killing the number of beetles they attract.

Yes we have used soil drenches as well as injections with mixed results on Lindens, Cherry, Plum, Roses (bout 200 high value hybrids) Birch, Bayberry. The trick is to get the product into the leaf before pest emergent and while we didn't see a significant reduction of damage most of the customers were very pleased by the applications. In areas where a foliage spray is not possible we still make ground as well as vascular applications. When a drench or injection is made at the right time combined with a foilage spray just prior to beetle emergence we have had excellent results. We have achieved an 80-90% reduction to Lindens when trees in adjoining properties were devastated. We believe this is because the initial emerged beetles were killed on our plants while at the neighboring properties the beetles released the pheromone that says HAY THEIR IS FOOD AND SEX HERE. As to the rates check here http://www.bayercropscience.com.au/products/list.asp?fun=insecticide I guess what I'm saying is that drenches and injection can increase plant protection when properly timed however they are (for us) only another tool and are not for us a replacement for the foliage spray.

tremor
01-26-2008, 03:31 PM
Systemic insecticides can also be delivered right into the vascular system via the trunk. If using a Wedgle or dilling holes is of concern (is with me) then you might try PentraBark. Treat only the trunk from the 5' down to the flare. Imidacloprid is still slow. Depending on conditions it can take a while to cause knock down.

Actually, Imidacloprid is weak on adult scarab beetles under the best of conditions.

Watch for the new & improved Safari label some time this summer. Combined with PentraBark there is no quicker, easier or more effective way to treat even large specimens without concern for off-target sprays or soil drenches. New Yorkers will predictably be waiting a while longer than everyone else.

Safari & PentraBark is already approved for Emerald Ash Borers in those states so afflicted.

Russ
01-26-2008, 03:37 PM
Systemic insecticides can also be delivered right into the vascular system via the trunk. If using a Wedgle or dilling holes is of concern (is with me) then you might try PentraBark. Treat only the trunk from the 5' down to the flare. Imidacloprid is still slow. Depending on conditions it can take a while to cause knock down.

Actually, Imidacloprid is weak on adult scarab beetles under the best of conditions.

Watch for the new & improved Safari label some time this summer. Combined with PentraBark there is no quicker, easier or more effective way to treat even large specimens without concern for off-target sprays or soil drenches. New Yorkers will predictably be waiting a while longer than everyone else.

Safari & PentraBark is already approved for Emerald Ash Borers in those states so afflicted.
Tremor Good to see ya on here

I have no experience with PentraBark but have heard rumors it will kill grass and can discolor the bark. Any truth to that?

Whitey4
01-26-2008, 04:03 PM
First, it is the use of the word drenching I don't like. I know that this treatment has it's place. Secondly, milky spore DOES work! The key thing is that the soil temp has to be at 70 degrees of higher... which is a problem in the midwest perhaps. Back in the late sixties, Long Island had a virtual plague of Japenese beetles. What wiped them out? Virtually every property was treated with mikly spore. In two years, the population had dropped to very tolerable levels. It works, and it's not "hokus pokus". It won't work if the population is small however. The spores need a sufficient food source to be effective.

I had a friend in Wisconsin... she was growing rasberries on a small farm. The plants were getting completely destoyed. She went through all the ground and foliar treatments there were, but still the damage ruined her crop. She did all her local cooperative suggested. She ended up buying about 25 ferimone traps, and placed them at her back forty... about 500 yards away from her rasberries. It took her two years, but she knocked the local population down by about 90%. No adults to lay eggs, no grubs. I certainly would not suggest the use of traps unless as a last resort, and never on a small property. For her, it was traps or give up on that cash crop.

tremor
01-26-2008, 04:33 PM
Hey Russ,

I still poke my nose in once in a while. There is significant entertainment value at times that is just irresistible. :rolleyes:

All surfactants have the potential to burn turf that is under drought stress. However we're not treating turf with this application. A low pressure (hand-can) treatment of the trunk is all that's needed. Slight turf overspray should be avoided (label?) but doesn't pose a significant risk to turf health under the conditions present when these treatments are likely to be made.

Discoloration of the bark? This rumor is 100% Hogwash started & perpetuated by a company with a stake in a competitive delivery system. We have California Oaks that were trialed with up to 25 bark treatments in a single season with no injury or discoloration (Agrifos + Pentrabark for SOD). Email me for the straight dope if you want it.

Here in New England Agrifos & Pentrabark are already used widely for Beech Decline & I've never observed any discoloration. I have seen Beeches killed by secondary infections via injection holes so this new technology has significant value to conscientious arborists.

Silver Maples that are treated with Pentrabark might demonstrate a minor & temporary lightning of bark just after treatment but it's not damaging & goes away pretty quickly. No other tree has demonstrated this.

Whitey4
01-26-2008, 05:24 PM
Hey Russ,

I still poke my nose in once in a while. There is significant entertainment value at times that is just irresistible. :rolleyes:

All surfactants have the potential to burn turf that is under drought stress. However we're not treating turf with this application. A low pressure (hand-can) treatment of the trunk is all that's needed. Slight turf overspray should be avoided (label?) but doesn't pose a significant risk to turf health under the conditions present when these treatments are likely to be made.

Discoloration of the bark? This rumor is 100% Hogwash started & perpetuated by a company with a stake in a competitive delivery system. We have California Oaks that were trialed with up to 25 bark treatments in a single season with no injury or discoloration (Agrifos + Pentrabark for SOD). Email me for the straight dope if you want it.

Here in New England Agrifos & Pentrabark are already used widely for Beech Decline & I've never observed any discoloration. I have seen Beeches killed by secondary infections via injection holes so this new technology has significant value to conscientious arborists.

Silver Maples that are treated with Pentrabark might demonstrate a minor & temporary lightning of bark just after treatment but it's not damaging & goes away pretty quickly. No other tree has demonstrated this.

Glad I could entertain you.

tremor
01-26-2008, 08:27 PM
That wasn't a shot at you Whitey. You've been asking good questions & learning which is why this forum was originally concieved. More power to you. Stick around long enough & you'll notice that there is a "roll" like waves on the beach. There are three phases.

Learning
Using/Teaching
Running away all burned out

Whitey4
01-26-2008, 09:01 PM
Well, the whole trap thing has a story behind it. Like I said, I have a friend in Wisconsin who has a small farm, and her most profiatable crop was rasberries. One yera, she noticed an increase in the population. The next year, she lost the entire crop. She was wearing a bee suit when she applied! She tried everything. Ground treatments, injections, soakings, drenching... even had a PhD from the coop come out to her farm.

He suggested that the beetles were coming from miles around, and unless the entire area was somehow treated, to give up on the rasberries until the population declined on it's own. Well, she's pretty stubborn. She put 25 feromone traps out, about 500 yards away from the rasberries. Said she was emptying the traps every three hours at first. About a week later, twice a day.

The following year, she repeated this. That second year, she was getting full bags only twice a day. She estimates that she collected about 1000 pounds of beetles those two years. That's 100 pounds of beetles that never laid eggs. Was that what worked? Was the population decline due to a natural cycle? I don't pretend to know. This is a simple case study with no controls at all. So, it's neither here nor there. But I know a farmer in Wisconsin that swears traps can work.

Admittedly, I base my posts on what Cornell says, and that is very geopgraphically specific. Case in point: In a link that Russ was good enough to PM to me, Perdue accepts the idea of preventative apps for beetles. Cornell does not. Localized issues, such as soil make up I suspect could be part of why there isn't agreement.

My friend in Wisconsin has clay soil. I am under the impression that this is true throughout much of the mid-west? Merit apps won't leach in that soil nearly as fast as it will in my sandy loam. Cornell says don't treat in the spring, with heavy rainfalls, and over wintered late instar developed larvae, it will leach too fast to kill mature larvae. They feel it just makes beetles and the new late summer larvae more pesticide resistant. They recommend only a late August or so (based on GDD and visable flying adult hatchings) application. Less rainfall, less leaching, more vulnerable newly hatched larvae.

In many ways, I'm glad Merit is now restricted here. They should restrict most stuff, since Harry Homeowner doesn't read labels, over applies, and at the wrong time. Next, it will be dylox, because that's the only thing they can still get their hands on.

I guess since I am in the part of the coutry that leads the way in making controls restricted and/or prohibited, I will try all sorts of IPM before applying.

Milky spore did wipe out the Japanese beetle here some 40 years ago, but I would not use it here now. Merit or dylox will kill the spores. Since our problems are now the European Chaffer and the Oriental beetle, milky spore really isn't an option. Having said all that, I won't offer any grub control in the spring. I just don't think it's a good idea here. It helps that both of these beetles don't feed as flying adults.

But, I did think it was worthwhile to mention what happened with my friend in Wisconsin. I do have to think she put a big dent in the local population. She had a bumper crop of rasberries this year... and no traps.