Topic: Japanese Beetles

[Paulines7]

We were astounded to find hundreds of beetles on our young trees yesterday.  I looked them up on the web and they are Japanese beetles.  They had eaten a lot of the leaves.  There are about 30 species of trees that they prefer and we have quite a few of those.  One particular favourite of theirs is the birch and we planted 20 quite recently!   :(   They also like cherries, willow and ornamental trees.  Fortunately ours are still only about 3 or 4 feet tall as they were planted last year.  The beetle grubs could have been in the pots when we bought them.

The only way to control them is to pick them off into a jar of soapy water.  We did this last night and I went out again this morning to get those that dropped off the trees as we were taking them off.  Only about 12 today.  I will have another look this evening.  They are also on our rowan which is 7 years old and too tall to reach.  Any suggestions as to how we can get them off?  Maybe I should shake the tree and have the chickens handy.   ;D

We intend to make some traps and have some instructions which I found whilst doing a web search.  The beetles evidently like bananas so that is one of the ingredients for the trap.

Has anyone else had problems with these insects?

[Georgie]

Hi Pauline.  I'd never heard of them so I had to look them up.  I'd use a hose pipe to shift the ones off the Rowan and keep doing it to keep the numbers down.  This site seems helpful:

http://www.ca.uky.edu/entomology/entfacts/ef409.asp

G x

[Paulines7]

A very good idea Georgie but, unfortunately, it won't be possible to get a hose pipe to the rowan as it is towards the end of our paddock.  The grass is about 3ft tall at the moment so once it is cut we may be able to see the beetles when they fall off.  Hopefully the cockerels will see them too. 

Here is a picture of the beetles and another one showing the damage they are causing.

[Georgie]

Good grief, that's awful.   :(  I hope you find a solution soon.

G x

[Paulines7]

That's the young birch.......you should see the young cherry trees.....absolutely decimated.  I think I will contact the RHS and ask about them.  I collected about 25 more today and fed them to one of the cockerels.  I put the 200 or so, that were collected a couple of days ago, down the loo but they wouldn't flush away easily as they floated to the top.  I was in trouble with my other half.  I didn't want to put them on the compost heap in case they had eggs inside them.  I wonder if their being here in such great numbers is a result of global warming.  :-\

[GrannieAnnie]

So so sorry to hear you've imported Japanese Beetles! They've been a plague in N America since before I was born and are massively destructive as you've found, not only to trees but, in our garden, beans and roses. Pole beans especially attracted them so they left the bush beans alone. Spraying with Sevin helps. Some folks buy very expensive hanging traps that emit a hormone which attracts the beetles by the hordes. The only problem here is the traps attract all the beetles from neighbors' gardens also. However, since you sound like you are the only ones with the problem perhaps that is your best bet. Your govt.agricultural office ought to be able to give you some guidance.

They'll lay their eggs anywhere but seem to prefer under shredded woodbark mulch in our garden and grow into thick white grubs.  We tried sprinkling milky spore powder but didn't notice any change.

[Paulines7]

I rang DEFRA this morning and the beetle we have is a Garden chafer phyllopertha horticola and not the Japanese beetle.  It was confirmed by my sending a photo to them.

He gave me some good advice though on how to keep the numbers down.  It seems it is a matter of keeping the grass beneath the trees short, picking them off when we see them and spraying the area beneath the trees with an insecticide in a few weeks.

[lorna]

 Pauline I Really hope you manage to keep them under control. Will the trees recover?

[Paulines7]

I hope so Lorna.  I think John spotted them just in time.  Our Stella cherries are the worst hit but they haven't quite eaten all the leaves.