Bramley seedling bugs
I have planted (2 months ago) a Bramley seedling apple tree which came on, I think, 2 year stock. All was well, it had blossom on it, then one day about a week ago I noticed the leaves were wilting. On closer inspection, the underside of each leaf was covered with tiny black insects. The same happened to my Stella cherry tree, (before the birds scoffed all the cherries - again, a 2 year old tree). I sprayed both with a proprietary fruit tree insecticide and the bugs died, though still visible, but the tree hasn't recovered and I'm sure with the next strong wind, the leaves will all disappear.
Why has this happened? I kept it well watered and we have good soil in Lincolnshire. The dog likes to wee against it, but would that be enough to kill it?
And what would be the cause of only a small number of apples on my other (Annie Elizabeth) tree?