Unwanted pest

[Greg F]

Hi Ive recently discovered these little things on chinese elms. Can anybody give me some info on what they are and possible treatments. Thanks

Greg

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[Ryceman3]

Looks to be some kind of scale insect. The insect itself is under the hard outer casing, sucking on your plant.
If there aren’t too many simply scrape them off with a fingernail and squash. If there are more than you care to deal with like that you can get plenty of ‘off the shelf’ treatments for these... Neem Oil being one of them that you spray onto affected areas.

[TimS]

Ryceman best me to it; scale insect. Easiest is to scrape them off as the hard outer shell makes spraying less effective. Scrape off first then spray to follow up.

[Greg F]

Thanks guys, I scratched them off after I took the photo. They seem to be filled with a white powder.
If they aren't removed do they kill the tree or closest braches. I think ive had them on cottoneasters before also.
Cheers

Greg

[shibui]

Any sapsucker will weaken any tree. Most will survive but heavier infestations can severely affect tree health.
The big ones like this are easy to deal with but you will also have lots of smaller young ones on the trees so you will need to look closely to find them all.
They can be difficult to deal with using sprays because the insect is protected by the shell so contact pesticides like pyrethrum won't kill them. look for something that mentions it treats scale. Systemics are very effective because they get into the tree so when the pests suck sap or eat leaves they are killed.
Any treatment will need to be followed up a few weeks later because new ones will have hatched out by then.

[TimS]

They will slowly weaken the tree and eventually kill off branches and potentially the whole tree if you just totally left it and it got a bad enough infestation.

Keep an eye on it and monitor to see if it returns. Keep picking them off and it should be fine.

[Greg F]

Thanks a lot for the replies Neil and Tim. I will be doing my best to keep an eye out for more of them.

Greg