I have a 'Discovery' apple tree which I planted 8 years ago. The problem is that every year the tree is subjected to aphids that cause really bad leaf curl, followed by balls of woolly aphids that appear on the branches (I rub these off as much as I can), followed by the codling moth damaging the fruit. In April I hang up the moth trap and renew the sticky trap and pheromone each month right through to August. I also thin out the apples in June so as to give plenty of room for each apple to grow. What else can I do? Should I be spraying the tree with a chemical to give the fruit a fighting chance in which case what should I use and when? I would welcome any help I can get to solve this problem!