Help with Black Needles on a Sylvestris Pine

[bandi]

Hello everyone, I’ve been struggling with a friend to identify what is wrong with his Sylvestris (scots) Pine.
Some of the needles on his pine have turned a very dark (glassy) green - almost black. We can’t really tell if it’s fungus. The first impression was, maybe it’s the black sooty fungus that forms on aphid secretion, but it doesn’t look like it. The needle tissue looks like something that might have frozen, but that is out of the question. They don’t look like they are covered in sooty mold. However, my hunch is that it is some kind of fungus. It looks a lot like when succulents get black fungus in the roots and die…
We’ve also noticed that the tree is leaking sap in many places, in spots.

Last year the tree was infested by afids, but that was treated and they are gone now.
The tree was replanted in April.
The needles started changing to this dark color 2-3 weeks ago.
The tree nevertheless shows good health. All candles are elongating as expected.

For now we’re treating with insecticide and fungicide.

Any help or input is helpful, thanks!

[AndyK]

Hi @bandi
If you had aphids they would have excreted a sugary substance on the plant. Eventually this attracts mould. The main thing is that you have candle elongation. You may want to hold off any pruning or pinching this year, and you may lose the old needles. As long as the tree survives it should be fine in a few years when it has old needles again. Watch out for ants, as they farm the aphids for the sugary substance.

[bandi]

Hey @AndyK thanks for pointing these out. Yes we’re well aware of what you said. This was our initial thought as well, but as mentioned, it’s not the sooty mold that develops on the aphids’ secretion. It rather looks like it’s something that comes from the inside, outwards, rather than that black mass that develops on the needles.