Ants Crawling all over lemon tree

[jazzlobber]

looking for any advice from green fingers amoungst us.

We have a couple of young lemon trees, in the back garden, they are in those 30litre, half wine barrel things, the trees are both about 1.2-1.5 m tall, not in great nick and not producing much fruit, although there is some potential for future lemon yield as there are many small (tiny) lemonettes.

its just shed most of the early spring flowers, but we have ants crawling over most of the trees i believe they are harvesting aphids as there's alot of aphids and bubbly bobbles on the branches,

What can be done, have the tree's had it? any recommendations

 

[Simon]

The ants are good. Treat the aphids!

 

[Pushka]

Ah, our radio gardening guru says that ants on a tree are a sign of disease. And they dont eat aphids. Apparently aphids get blown in on a northerly wind; not much you can do about them but they will go away.
Not being a gardener myself I cannot confirm whether this is true or not!

 

[Debt Junkie]

Ants climbing (anything) is often considered a sign that rain is coming.

Since I don't have many ants, I couldn't say.

If you're really worried about them, see if you can find out where they're coming from (water the ground and see what floats) and put some ant dust down ...

I've had a nest at the base of my peach tree since it was planted (1.5 years ago), it isn't affecting tree growth or production ....

DJ

 

[geoffw]

Ah, our radio gardening guru says that ants on a tree are a sign of disease. And they dont eat aphids.

They don't eat aphids. They harvest them.

http://en.wikipedia.org/wiki/Aphid

Some species of ants "farm" aphids, protecting them on the plant they eat, and eating the honeydew that the aphids secrete; this is a mutualistic relationship.

 

[Programmer]

As Simon says (et. al), the ants are not your problem. The aphids are the problem. Treat them.

However, you also state:

and bubbly bobbles on the branches

Now if "bubbly bobbles" means what I think it does, this is more worrying... and is likely to cause the lack of fruit. I think your trees are infected with the gall wasp. It lays eggs in the tiny branch crevices, and the larvae hatch in September (region dependent). Are there tiny holes in the bubbly bobbles? If so, they've hatched and it's too late to treat them. You can stop the amount of infection by hanging those yellow sticky insect traps during the spring. I get mine from Bunnies. There is no domestic spray that is effective against gall wasp. They came down from Qld some years ago.

The "bubbly bobbles" are the "galls". They look like bumps on the branches. The larvae are inside. You can try cutting the very top of the gall horizontally (about 1 to 2 mm deep) to expose them to air (they'll die), but if your trees have many of them it is best to prune it back at least several cm below each gall to a healthy branch. Keep an eye out for any galls that form later and prune. Your trees might look a bit weird for a while but they'll re-grow next spring (assuming you keep them healthy...). You can have a look at the larvae by cutting the gall as specified above. You'll see the tiny larvae and their little tracks as they munch. A bad infection will stop the tree fruiting, affect the growth, and left alone, can eventually kill the tree.

BTW, I've not seen many citrus in Melbourne that are not, or have not, been affected by these little buggers in recent years. If I can find a good link with pictures I'll post it.

That said, if it's not gall wasp then keep this for when, not if, your trees are attacked.

Cheers

PS. I've added a picture of a gall. Oh, the flower drop could be from some of the frosty mornings we had some weeks back or lack of water/fertilizer - unlikely to be the aphids or wasps.

 

[Pushka]

They don't eat aphids. They harvest them.

http://en.wikipedia.org/wiki/Aphid

Mutualistic means that they benefit each other; as per this: http://www.uri.edu/ce/factsheets/sheets/aphids.html

In some situations ants tend aphids and feed on the honeydew aphids excrete. At the same time, they protect the aphids from natural enemies. If you see ants crawling up aphid-infested trees or woody plants, put a band of sticky material (Tanglefoot, etc.) around the trunk to prevent ants from getting up. Do not apply sticky material directly to the bark of young or thin-barked trees or to trees that have been severely pruned; the material may have phytotoxic effects. Wrap the trunk with fabric tree wrap or duct tape and apply sticky material to the wrap. Alternatively, ant stakes, dusts, granules, or baits may be used on the ground to control the ants without affecting the aphids or their natural enemies. Prune out other ant routes such as branches touching buildings, the ground, or other trees.

So you need to get rid of the ants!

 

[Simon]

Spray the tree with white oil. It is cheapy and eco friendly.

Let us know how you get on.

 

[Programmer]

So you need to get rid of the ants!

Yes, ants will help spread (harvest) moulds and scales however the ants are there because the tree needs treatment from other pests (thrips, mealy bug, aphids, various moulds and scales).

 

[pursefattener]

Hey Jizz , if nothing else works then I would try peeing on the ants and their home base . As long as there is no electric fence around , right...

 

[Pushka]

Yes, ants will help spread (harvest) moulds and scales however the ants are there because the tree needs treatment from other pests (thrips, mealy bug, aphids, various moulds and scales).

Yup, which gets back to my original post! The ants are a sign of another disease!

 

[Programmer]

Yup, which gets back to my original post! The ants are a sign of another disease!

Yup, which gets back to my original post! Don't get rid of the ants, get rid of the disease!

Just love round circles

 

[jazzlobber]

thanks to everyone, yes i think the ants are harvesting the aphids and crawling all over but i also think there must be gall wasp eggs and larvae that have already hatched ages ago, the lemon bushes came with the house when we bought it about 5months ago,

so i think my plan of attack would be

i) use some tanglefoot as in pushka comment to discourage the ants
ii) severe pruning to remove all aphids and gall wasp evidence,

maybe next year!

i've attached some photos taken with mobile phone unfortunately its focus is not aimed on the target but the background and i dont think this can be changed on the phone, but you'll get the idea

thanks again all especially the programmer as i think you have nailed the gall wasp thing by the sounds/looks of it.

cheers

 

[Programmer]

Yep, some lovely galls there GL!

If you can, and if the plastic pots get direct sun, then get some acrylic paint (even spray paint is fine as long as you cover the tree) and paint the pots white. This will stop them getting stressed so easily via lack of moisture in summer. Some people even paint mature citrus trunks directly with acrylic (not oil-based) paint - works a treat! Lastly, give 'em a good dose of Seasol before and after heavy pruning. Note, Seasol is not fertilizer, its seaweed extract and a hormone "supplement" if you like. It'll strengthen them and make them more disease hardy. Don't fertilize at all until you see new shoots starting next spring.