Rowan Tree Being Eaten By Beetles?

dobergal

Hello,

I was wondering if anyone out there can help me figure out how to help my tree.

I live in Zone 4b close to Ottawa Ontario Canada.

I have a young (about 12') rowan tree in my front yard which has been in the ground now for 2.5 years.

The first year it bloomed beautifully and produced many red berries. This spring I noticed significantly less flowers and even less fruit being produced.

I took a closer look and noticed that something is eating the leaves. Sometimes stripping entire limbs bare.

I noticed something flying around near the top so I gave the tree a quick shake and about 30 beetles fell out.

One got in the house so I managed to get a good photo



I don't know if they're the ones who are eating the leaves, or they are eating the pests who are.

Can anyone help me out?

Thanks very much!

Attached Thumbnails

 

Brent Ferris

Typically adult beetles don't eat the leaves, they just replicate the pest far and wide. The most likely pest is Mountain-Ash sawfly, a yellowish caterpillar with a black head, that when frightened or disturbed stands up (essentially on back legs). Generally find them in groups and can strip a tree quite efficiently. Most of the mountain-ashes seem to tolerate at least zone 4. could we get a picture of the leaves (mountain ash has compound leaves and there could be 9-13 leaflets per leaf) and the whole tree, and the base of the trunk, and the site it is growing on. Typically, few flowers suggest a dry summer the year before(flower buds died(, or a warmup in the spring (buds flushing) followed by a frost (killing flushed buds).

Need more info. Unsure of beetle, looks a lot like a lady bug.If so, could have been eating aphids in the tree.

dobergal

Hello treeshaveneeds, thanks for the reply.

I have never seen any ladybugs like that before. It is about the size of a June Bug (so almost twice the size of the usual red/black ladybugs)
I also came across the beetles while walking the dog in the woods along the river yesterday. About 3 pairs were mating on a bunch of wild rasperry bushes which also had foliage damage.

I haven't seen any caterpillars or aphids at all on the tree and have looked quite throughly.


Photo of the entire tree.


Closeup of healthy leaves


Base of trunk. (Note: I do not use the weedeater at it's base)


Closeup of some damages leaves.


Example of some of the bare limbs.


A few berries. Very sparse all over tree. (Note: Rump of beetle in photo)


Example of bark.

I actually came across two pairs of beetles mating on the upper branches however it is quite windy today and could not get a clear photo. When I pulled the branches towards me about 10 beetles fell/flew away.

I am really at a loss as I would like to prevent any further damage and would like to ensure this doesn't occur again next year.

Any help/advice would be really appreciated.

Thanks very much.

dobergal

Sorry forgot to add this photo. I noticed now the berries are also being consumed. Unsure if by the same culprit.

dobergal

After much online searching, I discovered what the pest is. It's called the Japanese Beetle.A species which was introduced to North America in the early 20th century.

They are very destructive, eat foliage and more will appear where others are. Wikipedia suggests using a soap-water spray to get rid of the bugs which I might attempt.

Also Milky Spore disease can be used to kill the grubs which feed on grass roots. So I will purchase that as well.

If anyone else has experience with this pest, I would appreciate more suggestions on how to get rid of them.

Thanks!

Brent Ferris

Yep, I have heard Japanese Beetle is destructive, no personal experience with it. Sorry about wrong id, scale is often hard to guess.