small garden tree appears to be dying?

Hi there. I recently acquired a garden. This small tree was bare over winter but leafed nicely in spring. However.... Over the past month or two I noticed a bad smell in the garden near this tree. Like animal waste. I realised eventually it was coming from this little tree. I noticed half of it seemed to lose is leaves. They curled up brown and died dry with some exhibiting tiny yellow spots.
The dark leaves have since spread to the good side of the tree too. I think it's taking over the whole tree. I notice lines of ants move up and down the trunk but not sure that's related. Here are some photos attached. Does anyone know the tree name it what I can or should do?
Many thanks indeed

 

Hello mcgon1979 and welcome to GC. Is your little tree spiny? It could be a pyracantha grafted onto a stem to make it into a standard. If it is Pyracantha, then I'm afraid the disease could well be fireblight in which case you need to dig it up and burn it asap! Fireblight is a nasty bacterial, infectious disease for which there's no cure.

 

The ants moving up and down the tree suggests aphids/blackfly to me, the ants will be feeding off them. The aphids can also create a nasty smell. Try spraying the whole tree with soapy water and see if it improves over the next couple of months. Keep an eye out for the aphids later and spray again if necessary.

 

Hi Noisette,
Thanks for your reply. The tree isn't spiny or thorny. I've taken another close up of the healthy and sick leaves and maybe someone can identify it. And a shot looking from underneath.

 

Looking at the underneath of the tree, is there damage or disease at the top of the trunk? The picture isn't close enough to tell.

Sorry, I can't identify the tree for you.

 

Hi again Sheal,

Here is a closer image. I don't think there is any obvious damage really under the canopy on the trunk.
I've sprayed the tree with an anti aphid type spray I forgot I had, so I'll see if it improves at all or continues to deteriorate.
Thanks for your replies so far all. Much appreciated.

 

You're welcome.

Yes the tree looks sound if a little gnarled, but that is down to age. Did you notice any aphids on the tree, black fly tend to swarm together in blocks?

 

I didn't notice any aphids, but there are some small flies over it occasionally. However, it seemed to die from one side to the other progressively over weeks. Would pests not attack it randomly all over? I've no idea. I guess time will tell.

 

Yes, you are probably right about the pests being all over. It hasn't been accidently sprayed with a systemic weed killer has it?

 

Nope. No weed killer used in the garden.

 

Something similar happened to my apple tree, it just seemed to be dying on one side and yet still flowering and producing fruit on the other. Eventually I had the rotten side cut back and the tree surgeon who did it said he thought it may have been due to wind and frost damage as a neighbour had cut back other trees and it seemed as if it may have created a wind tunnel. Anyway, if it's any consolation my tree is producing fruit again this year although it is rather lopsided!

 

Well the ID has got me stumped...all the suggestions I would have made relate to evergreens. I'm pretty certain though that whatever it is it's suffering from either bacterial canker or fireblight, which probably entered by the wound at the top of the trunk. Being a lovely-shaped standard like that, it really isn't feasible to chop out all the diseased wood and spraying won't cure it.