blackcurrant bush has curled leaves with white stickies within

What do you mean by white stickies? If you mean something like a sticky web, it'll be a moth caterpillar of some kind; the eggs get laid on the leaves and mother sticks a "leaf roll" over them with web. Difficult to treat because it's hard to get the insecticidal spray inside the rolled up parts of the leaves, but I'd spray it anyway, and if there's not going to be fruit, you could use a systemic insecticide (means it gets into the sap of the plant and then into the leaves, stems and flowers, etc.)