Apple tree - is this aphids?

Some of my apple trees are suffering from leaf curling, followed by browning. Closer inspection reveals a dark mouldy/dusty substance underleaf and a number of insects, which I believe to be ladybeetles in various forms of development from larvae to crawling spikey thing to normal looking ladybirds.

Any ideas? Is it a type of aphid causing the leaves to look so unhealthy?

Phew...

Was v concerned it might be fungal or disease and spreading etc.

Is it best to leave nature to do its thing or try a spray?

I have the same thing on my apple trees at home, but am leaving them alone.  The ladybirds are on the march and feasting.

I mulch the trees in winter with manure and give them an occasional handful of pelleted chicken manure over the summer.  I reckon they are tough enough to shrug off a bit of aphid damage without me having to reach for the sprayer.  I may get a little less fruit this way, but I also get a lot more ladybirds.  I'm happy with that