How to treat scale on eucalyptus tree?

[Bet]

Good morning, 

Would you happen to know what is affecting my eucalyptus tree? It appears to be isolated to one large branch (offshoot of branches) rather than through the whole tree but I'm not positive because it's hard to see up high and it's a 22 year old tree.

There's a type of scale build up on the branches. The scale is dry and white in color on the outside but when you peel it off its red and oily on the inside.

There is an oily sheen to the leaves on the affected areas.

There's an oily sheen to the grass below the tree.

I have pruned off the affected areas and crossing my fingers. 

Has anyone experienced this problem with gum trees?

(Struggling with uploading any images, sorry.)

Thank you.

Bet

[MitchellMc]

Welcome to the Bunnings Workshop community @Bet. It's terrific to have you join us, and many thanks for your question about scale.

Certainly sounds like scale and possibly Gumtree Scale (Eriococcus coriaceus) which has a red fluid inside. Apart from removing heavily affected branches, horticultural oils are typically effective at controlling the spread of most scales.

If you have difficulties uploading images through the text editor (there's a little landscape picture image button at the top), you can send them to workshop@bunnings.com.au, and I'll post them for you.

Please let me know if you have any questions.

Mitchell
 

[Bet]

Hi Mitchell,

Thanks so much for your reply and your advice. It's great to put a possible name to the scale.

I've emailed you some images a short while ago, in response to your kind offer to post them on my behalf.

Please let me know if the images shed any further light on the scale and indicate a specific product that might suit for eradication.

Thanks very much for your help.

Bet.

[Bet]

[JacobZ]

Hi @Bet,

Thank you for the photos.

Looking at these photos, I believe @MitchellMc's determination is correct, and the earlier advice still applies.

Having removed the affected branch, you should isolate and dispose of it so the insects cannot transfer to any other plants. 

You should then monitor your eucalyptus tree to see if any scale returns and treat it with horticultural oils if they do return.

Let me know if you have any further questions.

Jacob

[Bet]

Thanks so much JacobZ. 

Having pruned off the affected areas, I will cross my fingers and hope I don't see them again.

It will be tricky/impossible to apply oils if an infestation does reappear, as the tree is very tall and the branches are so high up. I've done a little research, since learning from Mitchell that it seems to be scale and I think I might have to try a 'systemic insecticide' which seems to be absorbed by the tree's roots and can kill scale insects as they feed on the tree's sap, though the website I was reading said to use it as a last resort as it can damage beneficial insects. 😞

Anyway, thank you Bunnings, and MitchellMc and JacobZ. 👍