Imred:

If you put down milky spore last summer, you may not see enough Japanese beetles to give your Sevin a workout.

I renewed my milky spore in July, '07, and have seen so few JB's since then that I am able to give them individual names. Before that, it was nearly 20 years since the first application. The stuff lasts a long time, so long as it can find a few larvae in the soil to infect and propagate its spores. I did my son's place a month later with one leftover 44 oz. can, covering 3 acres with small applications on a very wide grid of over 10 feet. It didn't seem to make much difference how much I applied, so long as I covered the entire area. He has not seen any beetles since either, after a really severe infestation earlier that summer. He was filling up 6 of those traps every day.

The names that I give the JB's are not nice names.

Don Yellman, Great Falls, VA

Don, what's your method of application? I just spoon it onto the ground and have someone follow me with a hose to water it in.

Alan:

I use the tube applicator supplied by the same company that makes the milky spore. They are located in the little town of Orange, Virginia, between here and Charlottesville.

The tube is about $10, and is just heavy cardboard, but it lasts a long while and saves a lot of measuring and bending so is well worth it for a large area. The business end has an adjustable opening like a spice can, and you just go along bumping the end on the ground. I like to work when the grass is very dry to prevent the product from clumping up in the opening. You can cover a lot with just one filling of the tube, which is carefully done with a teaspoon.

This works only for the pure product, of course, not the dilute MS mixed with kaolin that is applied with a spreader. I think the pure stuff gives you a lot more coverage for the money, but for a small area the spreader applied stuff is fine. I have never watered it in. It seems to take care of itself.

Don Yellman, Great Falls, VA

Don, that would be great if it controlled them. I was watching a thread on them last yr and saw where you had used it with success and that prompted me to try it.

I put down Milky Spore last summer... put it down before a rainy period if you can. I took a tablespoon and just put a clump here and there...trying to space it out like the directions say. I have Rose Chafers and Japanese Beetles and so far i'm seeing a million Rose Chafers, so i'm doubting the spore works on them, plus when i was digging this spring i saw the grubs in the lawn, so they were alive and well. I'll see how it works on the Japanese Beetles. They are new here and i only get a few (hundred).

The stuff is expensive and the research is iffy, but i guess its worth a try if you have some extra money. I still think mass trapping might work just as well, if you give it a few years or just stick with spray. Sevin kills them dead... i've used it before. Plus it seems to last a while.

I don't mind too much having to spray for plum curculio and coddling moth in spring but applying Sevin 2 or 3 times in dead summer is a royal PIA. Then the Sevin kills my beneficials and I get mite outbreaks and have to deal with that.

The evidence about Milky Spore isn't sketchy as far as it's ability to colonize soil and kill Jap beetles from what I've read. The problem is if the beetles fly in from nearby untreated lawns and occasionally defective product.

I do have one site where there are 2 large orchards less than a quarter a mile apart and one orchard get's terrible
infestations while the other only a few beetles, so they don't seem to travel far.

Like Don, I had terrible annual JB pressure on my own property and the first season after MS application the population was way down. By the second season there were just a few, but I've forgotten their names. Now after 20 years I've still not had a return, but I gave the lawn a little refresher last fall anyway.

I guess it might work if you could treat a square mile or more...

These guys say they can fly 10-15 miles from where they hatched:

http://web.extension.illinois.edu/livingston/horticulture/i2693_416.html

I don't care so much about Japanese beetles, we'll get a real winter again in this state that will kill off most of these overwintering grubs.

If you really want to know when Japanese Beetles will show up, watch the growing degree days. Its like clockwork with these demons. They start to hatch around 1029 GDD (base 50F)...I'm nearing 500 GDD here...so still some time before they pop.

Frank:

With all due respect to the Univ. of Illinois and their extension service, sometimes stuff like this is written by grad students who have very little dirt under their nails. I don't believe Japanese Beetles fly very far at all, and usually hatch out right beneath the plants they attack.

I have neighbors on three sides, and all of our lots are one acre. None of my neighbors have ever applied milky spore, but I purchased plenty of it and went about 30 feet into their yards when I applied, and that was it. By the second year, not only were my JB's eliminated, all theirs were too. My conclusion is that the range of activity of the spore continues to expand so long as it can find living larvae in the ground to infect. In my case, the MS eliminated not only JB's, but the chafer beetles as well, which was a result I did not expect. I know when the chafer beetles are gone when there are still leaves on the plum trees.

With all the "information" available on the internet, you can always find reasons not to do something, but usually don't know for sure until you try it yourself. I think it is important to purchase fresh MS and put it down right away, since this is a living product with a short shelf life, much like Bt. I ordered mine in from Yardiac.com, and it was very fresh. The most interesting surprise I had with the last application I did on my son's place was that the amount and spacing can be far, far less than recommended on the label. I covered 3 acres with one 44oz. can, didn't really expect it to work well at that rate, but it was 100% effective.

Don Yellman, Great Falls, VA

The sell Milky Spore at Home Depot here in La Crosse now. I saw it when i was in there last time. I'm not sure what the price was.

I really have no beef with them yet, and i hope my winters can keep the grubs in check. I've got Rose Chafers to worry about (now flocking to my trees and breeding by the boatload).

What Cornell says about Milky Spore efficacy is that harsh winters in colder zones can kill it off. I'm supposed to be a bit north of the line but -22 a couple of times during a test winter didn't seem to hurt it. 12 years later and no JB's.

You do have to take research based information with almost as much salt as anecdotal- especially in horticulture with all the variables.

Frank, I don't know if you are reading what I posted carefully but what Don says about the relative short flight areas of JB's certainly coincides with my experience, which is considerable in terms of sites and seasons. Same for Don, of course.

I was talking with the extension person about the japanese beetles, and they said the milky spore doesn't do much here. He said that what happens is that after the beetles have been in an area for a while that their numbers start to naturally decline. So after an area has been infected with beetles for about 10 years their numbers will go way down. But the milky spore doesn't do much in small area since the beetles are usually coming in from parks or golf courses that water their grass in the summer. Of course, I'm on year 4 so I've got millions of beetles.

Based on Don's advice, I put down 2 of the 40oz cans using the tube applicator on a really wide gird over about 5 AC and watered most of it in with a hose. I've got about 25 AC of untreated pasture right next to the treated area and the beetles were not much of a problem the next year (about 20% of the years prior when some young trees were completely defoliated). I've had other people tell me that last year was not a bad year for JB's, so it is hard to gauge the effectiveness, but my drop was so huge that I'm currently a believer.

Harvestman-

If you read personal experiences on this stuff from people on the internet, the results seem all over the place. I did a ton of research last summer (this stuff isn't cheap..its hard to produce or something)..i'm not rich and throwing money away isn't my lifestyle. I did feel like i made a mistake after ordering since i have such a small area i can cover and all my neighbors nice manicured lawns could be harboring grubs.

I don't work for St. Gabriel Organics and i'm not trying to sell this to anyone, its just my experience so far.

Athen-
Your in Madison? They are pretty bad there? I know a guy from Milwaukee who says he doesn't have them, which i find hard to believe considering IL is full of them and their winter low temps are very mild (this winter i don't think MKE dropped below 0F).

Yep, I'm in Madison. The beetles are still a bit patchy around here, some areas like mine are really bad but others don't have much. I did try Milky Spore two years ago and haven't seen any difference yet.

As a side question, did any of you notice a reduction in mole activity? I'm pretty diligent on spraying at first sign of JB and usually keep them under control; however, I do suffer an awful lot of mole damage.

Brook

My dogs are the mole/vole/shrew/mouse killers so I have never had a problem with them.