Elm Disease and Elm Leaf Beetle

[dandybonsai]

On the road today noticed a sign in relation to Elm leaf beetle should anyone buying plants in this family group of plants spray purchase's as a matter of protection?Any thoughts wether it is wise to do as a hobby,possible seen as leaders?

Should any people heading back from oversea's be spraying their clothing/ bodies for prevention of spread of Elm Disease,not many countries seem untouched,is it best to leave clothes in the diseased Countries??

[Naimul]

i remember someone telling me elm beetles are not much of an issue for bonsai, as the trees are fairly low to the ground and generally not in the flight path of the beetles. Also depends what is happening around you too, like outbreaks and so on

[alpineart]

Hi dandybonsai , mate i spray my bonsai here for Elm leaf bettle every year and contrary to suggestion they do attack bonsai small and large .Weeds spread accross and interstate from soil with seeds are a bigger problem than the bettle up this way .We do get the bettle every year but its only a seasonal occurance , weeds grow all the time .

As for leaving clothing behind shari there is more supperior bugs to worry about than Elm leaf beetle . Maybe we should put humans in quarentine for say 3 months to de-bug them .

Cheers Alpineart

[shibui]

I also have elm leaf beetle eating the leaves on my English elm bonsai. I did not spray this year but will probably have to next year because there will be even more hatch out of the soil.
Remember that elm leaf beetles can fly so even if you initially spray the tree, more will come in from neighbouring trees.

Even if we were to quarantine clothes, etc to keep out Dutch elm disease some fool will illegally import plant material so eventually it will arrive here Take note all those who have ordered seed, etc through internet sites

[Brian]

Does Elm leaf bettle affect Chinese Elms ? I have two large specimens in my front garden.

[alpineart]

Does Elm leaf bettle affect Chinese Elms ? I have two large specimens in my front garden.

Hi Brian , mate i had issues with a very large bonsai "Chinese Elm" also "Ulmus Glabra" and Zelkova a few years ago all are around the 1 metre mark , however they didn't touch the smaller bonsai . Since then I now spray early in the season , there has been no sight of the beetle here however they have stripped the tree's "English Elm" and "Glabra" just down the street .

Cheers Alpine

[dandybonsai]

My main problem i see with the Elm Disease is alot of people holiday in New Zealand and it is such a small amount of time for the disease to catch a ride to Australia,not sure what checks are made at border but on my trip a few years ago we had dirty footwear,clothes etc and were passed even that we said we had soil clothing.( i think its when it happens as alot do holiday there)

My subject is more feedback to the problem of beetle's due to buying stock with them included.
Is it better to change the soil late winter incase,more are in soil,pots are atleast 2 years old?
I was thinking to wash all soil away September than putting tree's under water for 20 minutes than repotting with fresh mix,doe's that seem a good way or will the tree's die?

Is there a chemical free way to treat the tree's without possible adding harsh chemicals to the enviroment?(above idea to be submersed in a bucket of water able to kill bugs??) I have looked over 3 plants every 3 days can't see any other signs of them but the beetle's will be closing down for a sleep to big to sleep in bark but lots of spots in mix.

I remember reading in a paper maybe 15 years ago at Bacchus Marsh,that around 20 trees and shrubs can be eaten by the bettle's just they prefer a few select type's over the others.

I have had alot of time in quite at a few Avenue Plantations in Victoria and it is heart breaking to see such old tree's die from the beetle's lets hope Elm Disease doesn't arrive as we have alot of lovely tree lined streets,and our Bonsai's.

Beetle's are easy to see on our tree's, as long as we look for the eggs(depanding on your area from last week of October,generally laid on underside of leave's,my first purshase came with a egg and beetle...won't name seller)

Reading via a council site that the beetle's can have 3 lifes cycle's in a good season no wonder some tree's look bad.

Thanks for feedback so far.I hope you can give me any feedback on my none chemical idea's,i do try to stay away from chemicals if i can these days.

I try to make my own homemade soil conditioners etc from food waste and garden waste cuts down the need to go to the tip that i used to do alot when younger.

I'm a organic lover these days,i used to be the chemical lover till a blood test made me steer away from chemicals were possible.

[shibui]

I understand the life cycle of elm leaf beetles to be:
beetle lays eggs on the leaves (spring- summer)
grubs (and adult beetles) eat leaves (spring-summer)
When grubs are fully grown they climb down the trunk then dig into the soil to pupate (summer- autumn)
Late summer generations overwinter in the soil as pupae (winter)
New beetles hatch, dig out of the soil and fly to trees, feed, mate, lay eggs (spring-summer)

In winter all are pupating in the soil so I guess that removing all the soil will get rid of many of the overwintering cocoons. I think the trouble will be that it is difficult to get all the soil out of a root ball so some will remain. i do not know if they stick cocoons to roots,etc that might make it even more difficult to wash them off.
I do not think that submerging in water would kill cocoons. The pupae is reasonably dormant and usually protected by a waterproof cocoon and will probably survive quite a while under water but do not know for sure or how long they can last under water.


Chemical free control:
Elm leaf beetles can be trapped with sticky bands around the trunk during summer and autumn when the grubs are traveling down the trunk to pupate in soil. This is very effective on garden trees but might look a bit unsightly on bonsai.
Monitor trees regularly and remove grubs and adults.
Not sure whether BT (Dipel) affects Elm Leaf Beetle. It is a naturally occurring fungus that kills other caterpillars but not harmful to anything else. Would be worth trying.

No chemical free methods are 100% effective and most need commitment to maintain. New beetles will still fly in from any nearby trees.
Good luck with the search for answers.

[Peterji]

I tried leaving my clothes behind when returning from overseas but they wouldn't let me on the plane without them