I guess I've been lucky during 35 years of gardening - this is the first time I've had to deal with Japanese beetles. They're decimating my grape vine leaves. I doused them last night with disgusting, fermented garlic/onion spray that I made last year, which chased them away. Are they a short-visit pest, or do they tend to move in with their furniture and extended families once they've found a snack they like?
Look into milky spore disease. If neighbors don't bother at least the grubs in your yard will be less. Slow acting but lasts years. We have used those yellow traps. Just be sure to place them far away from your plants.
We don't have them about this year. Knock on wood :)). No gyspy moths either. Seems cyclical.
Joe,
I've endured the beetles for over 3 decades. My approach is peaceful co-existence. The grape leaves look ugly with all of the holes in them, but my crops have always been excellent in spite of the damage to the leaves. In my warped opinion, every hole in a leaf just creates an opportunity for the leaf below to get more sunlight. :)
Very seriously, I don't see any real harm to the plants. Currently, the pesky little bugs are eating my grape leaves for energy, humping one another, and then dining on grape leaves again. Sort of like the insect variety of college students. :)
I still get a great crop and my bigger concern is the bees, wasps, other insects and birds who will be dining on my crop when it matures. That is much more serious. Nets help with the birds, but it is very difficult to keep the insect away.
After the vigorous breeding on my grapes vines, the beetles will move on to deposit their eggs on my lawn and the lawns of my neighbors. The subsequent grubs are a non-trivial problem, but I've even learned to live with that. Of course, that means that there will be a fresh crop of beetles down the road to repeat the cycle.
You are extremely lucky if you've grown grapes for 35 years and you are just encountering Japanese beetles. Others may disagree with me, but I seriously suggest that you just see how you crop turns out in spite of the holes in the grape leaves.
FYI: every year my grape leaves look as if somebody blasted them repeatedly with a 12 gauge shotgun. Ugly, but still very productive.
Treating your lawn for grubs may mitigate future problems, but not very much unless all of your neighbors do the same. Grubs in any nearby lawns will probably produce beetles who will feast on your grape leaves next year.
Good luck, Gideon
PS: Don't forget to harvest some of those tender young grape leaves early next season before they turn tough and before they get eaten by bugs. There are many great uses for tender young grape leaves. I share mine with several neighbors, most of whom reciprocate by sharing the delicacies that they make from the leaves.
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I have no intention, by the way, of using any treatment other than my current garlic spray, or perhaps the appropriate milky spore concoction. I'll probably crank up the garlic/onion thing with some cayenne, once the peppers get a bit riper (I'll probably have 8 billion peppers ready in two weeks). I'm just concerned because these grapes were just planted this season, and I don't think they can afford to lose MUCH leaf volume. Later, when they're monsters, I agree that some leaf loss won't be a big deal.
Is insecticidal soap effective at all against these bugs, or do they just laugh at that stuff?
In my experience they become homesteaders.
Time for the propane torch....
For young grape plants I would be a bit more concerned, but they will still survive rather well.
FYI: I examined my grapes this morning. Some leaves look like green lace. About 98% of the green on some of the leaves is gone. Other leaves look robust and untouched.
My college-aged son enjoyed cutting mating pairs of beetles in half with the pruners, more for fun than for protection of the grapes. PETA will probably be filing a complaint.
If you already have the materials for spraying, then I'd suggest proceeding. Just remember that plants are very resilient and the grapes will survive quite well and the success of next years grapes will be unaffected.
Once again, this is just my opinion: I try to avoid creating more gardening work then necessary. There are pests, diseases and so many other problems that I just force myself to ignore the minor ones. For me, beetles having a lunch on my grape leaves is one of the more minor problems. I'm not trivializing your concern; just presenting my perspective.
Good luck, Gideon
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Is insecticidal soap effective at all against these bugs, or do they just laugh at that stuff?
I agree about the extra work. And, the beetles are the least of my concerns. The deer are another story. In NY, it's legal to kill any animal which destroys food crops. Unfortunately, where I live, there's no safe (or legal) way to do that with a firearm. All other ideas have been exhausted. I may be out there with a baseball bat and an axe in the next few nights.
I you are adverse to using Sevin, there are traps. But, don't do the stupid thing I did and hang traps near the grapes. Place away from crops you want to protect, otherwise they snack before going to sleep in the trap.
Frank
Frank wrote: But, don't do the stupid thing I did and hang traps near the grapes. Place away from crops you want to protect, otherwise they snack before going to sleep in the trap.
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Good advice. The traps attract beetles and that's the last thing that you need when the bugs are already attacking your crops. Find a neighbor you hate. Conceal the traps on his property. :)
Gideon
I think you're spinning your wheels :) Read this following bit of history from the early 1900's on the attempts to quarantine the new pest:
From what I have observed in my area (beetles have been here for ~8 years) they seem to really like grape vines. At least the wild variety.
Oh great. I wonder who likes to eat them. Probably no animal anywhere in MY neighborhood.
Johnny Borborigmi wrote in news:2006072306203577923%growl@tummycom:
I gave up on the traps. I caught thousands of beetles in them but I found a bad side effect: at mid day my lawn would have hundreds of beetles buzzing over it, with clusters of 30 or more in some kind of orgy actaully on the lawn.
I have never seen this behaviour prior to employing the traps and it went away when I took them down. I also observed the beetles eating my azaleas and dwarf spruce new growth. Again, never seen this in prior years and it stopped when the traps were taken down.
The problem now is I feel like I *have* to use a chemical on the lawn for the first time, thanks to the traps. Yes the traps do catch beetles, but they bring way more to area.
Bill R wrote: I gave up on the traps. I caught thousands of beetles in them but I found a bad side effect: at mid day my lawn would have hundreds of beetles buzzing over it, with clusters of 30 or more in some kind of orgy actaully on the lawn.
I have never seen this behaviour prior to employing the traps and it went away when I took them down. I also observed the beetles eating my azaleas and dwarf spruce new growth. Again, never seen this in prior years and it stopped when the traps were taken down.
The problem now is I feel like I *have* to use a chemical on the lawn for the first time, thanks to the traps. Yes the traps do catch beetles, but they bring way more to area.
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I agree with everything that you have said. If you really hate a neighbor, then purchase the lure from the Japanese Beetle traps and covertly toss it into his garden. :)
Seriously, the traps attract so many beetles that it outways the much smaller number of beetles which are killed.
Gideon
Since I hosed down the grape vines last week with disgusting year-old fermented onion/garlic/cayenne solution, there have been no beetles, even after 4 hours of heavy rain which should washed the stuff off. I doubt my luck will last, but I'm just saying...ya know...maybe.
Some have told you not to worry about the riddled leaves but I take exception to this. The Beetles feed on the new leaves and tender shoots. THIS is where most of the photosynthesis is taking place for the grape vine. Grape leaves have a productive photosynthesis life of 60 to 90 days. After that, the young leaves take up the work load. You may not realize it, but your vine is suffering from not having healthy young leaves if you let the beetles have their way.
I use Seven. If you do, wait at least 7 days before harvesting your grapes. For me, this is no problem because the beetles are usually gone around mid August and I do not harvest until late September to mid October (wine grapes)
I took all that "riddled leaf" advice with a grain of salt. As far as the Sevin, I won't use that. But, the hideous onion/garlic spray seems to have done the trick for now. I have not seen a single beetle on the plants since my first message.
I spray mine with this.
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