Apple scab affects both the leaves and fruit. It could be something else but to tell we'd need more to go on. Here is a link that might be useful: apple scab pictures

This year is a terrible year for black spot & fungus diseases not to mention bugs. My apple trees look like this also. There are 3 possibilities and probably all 3 are the cause: Fungus, Bugs,& nutrient deficiency. In order I do the following: Use GreenCure, www.greencure.net for the fungus possibility. Two, Liquid Seven for the surface bugs. Yes, I know its a chemical, however, there are very few alternatives in the organic market. Also for the underground bugs, I use beneficial Nematodes to put in the ground. These are microscopic worms that eat the larva & pupa from the inside out and spread. Completely harmless to human and animals, plants. These puppies eat over two hundred different types of bad bugs in the ground. Contact Jennifer at Vammi Beneficials. www.vammibeneficials.com and mention my website link below for a 5% discount on your order. Lastly, the nutrient deficiency. It's too late in your zone to fertilize. Fall will be here tomorrow and I would suggest leaving this alone until next spring. Use some 10-10-10 fertilizer in moderate amounts and wash in thoroughly. Here is a link that might be useful: Green Anything !

When were these trees planted? To me, they don't look too bad at all. The leaves are curled but still nice and green. If I had to guess I'd say there's a bit of water stress going on. I'd say your trees' root system aren't able to get enough water to keep the leaves from curling, either because there's not enough water or those roots simply aren't established yet. Likely the latter. Don't overdo the watering. I would suggest some slow, deep watering. If you have a 5-gallon bucket, drill a tiny hole on the side near the bottom, fill the bucket, and set it above where the roots are located. Let it drain overnight, the slower the better. You might also find this a good time to do some summer pruning. Those branches look like they could use some cutting way back. That would reduce the workload on the roots and possibly balance your trees' root systems vs their tops. If they were recently planted, the roots likely are behind in development compared to the tops.

I knew what it was, but not having had to deal with them didn't know much about it. I read a bit online and as fruitnut said, they are indeed difficult to control. There is one insecticide acephate (Orthene), that kills them. I understand what fruitnut is saying about not doing anything, but if it were me...I'd do something. I couldn't leave that alone. I did read that insecticidal soap or dormant oil spray may do the job. Normally, I'm not much for soaps and the like, but in this case I can see where that might just be the ticket. Apparently their waxy bodies protects them quite well. This may sound silly, but I wonder if you mixed one two of those small 50 cent bottles of Elmer's glue into a quart or so of warm water then added a tablespoon of sulfur if that might do the trick. Maybe forget the sulfur, I just kinda view it as a cure-all and I know it's deadly to aphids. I think the glue would bind them because of their feathery bodies. The glue should be harmless, if not beneficial to the tree. Anyway, if it sounds goofy forget it...just me sittin' here thinkin'.