Being responsible caretakers of our environment, we removed a 12-ft. tall invasive burning bush (Euonymus alatus) from our foundation after buying our home a year ago. It is illegal to sell them in New Hampshire. The seeds are scattered by birds and the plant is out competing native plants in the wild.
The burning bush was replaced with a native arrowwood viburnum, one of which grew in my Virginia gardens. It produces lacy white flowers in the spring and berries for the birds in the fall. I thought I tackled the right questions about this beautiful shrub at the nursery but we already knew a bit about their versatility. The shrub is tolerant of sun or shade, all soil types, wet or dry areas, and is pest resistant. It sounded like a perfect addition to our shrub border…. that is, until this week.
It seems the shrub isn’t so resistant to insects. Japanese beetles love this species of viburnum! Never in Virginia, but here each morning, it’s a mating and dining Japanese beetle playground. And there’s evidence of a more sinister insect at work, the Viburnum Leaf Beetle. This is a beetle that I have not encountered before. Now I’ve spotted a couple of the insects and witnessed their telltale pattern of holes in the leaves.
via Wikipedia
I’m watching and speculating what our next step should be. Sadly, this beautiful shrub may need to be removed in the fall and replaced with a more insect resistant variety of viburnum. Sigh….
Do these varmints have any predators?
I know those Japanese Beetle traps work great.
Sure hate to spray. How about a systemic something.
Glad we don’t get beetles in Virginia, well, since we got
rid of roses!
LikeLike
I’ve never used the Japanese beetle traps. Many feel the pheromones attract a larger number of beetles from afar. At best, it traps 50% of the insects and the others chow down on plants. And I don’t spray.
LikeLike
Viburnums with hairy leaves tend to be more resisted to viburnum leaf beetle great post.
Jon
LikeLike
I don’t see any signs of them on my doublefile viburnum. Whew!
LikeLike
Insects — a gardener’s little problems…..
LikeLike
I do love to discover new insects. Just wish the viburnum leaf beetle wasn’t so destructive!
LikeLike
Hang in there Annie! As long as those pesky beetles don’t chew all the leaves off, you may want to keep the lovely Vibernum. Soon they will be done mating and going back to the ground to lay their eggs. We have this happen every time around the fourth of July and they swarm certain bushes and dive bomb you in the evening. For smaller shrubs I use organic Neem oil, which is both a fungicide and an insecticide that is harmful to bugs who eat the leaves, but not to bees and other pollinators as long as you spray it in the evening and it dries before morning. The downside to Neem oil is that it needs to be applied every couple of weeks or after a heavy rain.
And once they are back in the ground you can use either grub ex or milky spores to try to control the grubs that will then try to eat the roots of your grass! Good luck
LikeLike
Thanks for the advice on pesky Japanese beetles. Neem oil is something that I have but didn’t realize it could be effective for jb. Milky Spore bacterium certainly worked for us in Virginia. Sad to learn it is not as effective in cooler climes. But not convinced we have a grub prob. I have not seen them when I dig around the yard.
LikeLike
Sure some Viburnums are resistant to this Beetle. Spinosad will control them and is considered organic. Spinosad is the active ingredient and it has many common names, Captain Jack I believe is one of them. Spinosad will kill bees when they are sprayed with it, but not when dry so treat late afernoon after they are gone or after they have finished flowering. The Viburnum leaf beetle lays its eggs only on the ends of branches, until sometime in late August to early September. You can see them lined up in a single row. They do not become “white grubs” in the soil. If you prune off 10-12″ of the branches after September and before April you will get rid of a lot of the problem. Of course they do fly so some will find you again from plants close by.
Link to life cycle http://www.hort.cornell.edu/vlb/
As a side note to the post above: Milky Spore will absolutely NOT work this far north, southern Ct is about as far as it is effective, so don’t waste your money.
IPMMAN
LikeLike
I will certainly be on the lookout for telltale signs of the viburnum leaf beetle and the eggs on the ends of branches. I am aware of Captain Jack Spinosad bacterium but haven’t used it…. yet!
LikeLike
It needs to be applied in the fall not the spring and late July early August would be your fall.
LikeLike
Spinosad needs to be applied when the beetles are present in the spring. You will have to apply it every couple of weeks if you see more beetles. Imidacloprid “Merit” is applied to the soil late summer early fall to get into the plant by the time the beetles hatch in the spring. Imidacloprid is a neonicatanoid and will be transported to the pollen of the flowers where it can kill foraging bees.
IPMMAN
LikeLike
The milky spore. See above post.
LikeLike
For an organic control that will not kill off honey bees or other pollinators that we really need, here are some links I have recently researched. Milky spore is effective, now is about the time to start using it. The viburnum will come back next year. I love them!http://www.wtop.com/902/3660277/Attack-of-the-Japanese-beetles-Eradicating-them-the-safe-and-easy-way
http://mattswisdom.com/tag/grubs/
https://ag.arizona.edu/pubs/garden/mg/pesticides/environment.html
http://rockydale.wordpress.com/tag/milky-spore/
https://docs.google.com/gview?url=http://www.soiltechcorp.com/turfprod/Milky-Spore.pdf&chrome=true
LikeLike
Now we are talking about Japanese Beetle as Viburnum Leaf Beetle do not form white grubs.
Milky spore will absolutely not work much past southern Ct. On exceptionally warm years it may work on the coast of NH but I would not bet on it. Nematodes can work well if they are applied properly and cared for if the weather does not cooperate.
Google has a Scholar setting which is not as easy to get to as it was but you can find it. It filters out real research by scientists from the chaff of people trying to sell you something. One should never accept what they see on the internet (including from me) as the fact without checking scientific data. Google scholar really helps here.
By the way one tip that I rarely see when people are discussing natural white grub control is watering. If during the adult flight season you are willing to keep your lawn a little dry then the adults will choose other places to lay eggs. And never water during the setting sun. Adult beetles fly towards the setting sun and look for moist spots to lay eggs.
IPMMAN
LikeLike
Reblogged this on By the Mighty Mumford and commented:
OH WELL…!
LikeLike