Aphids are easily controlled with insecticidal soap, look for Safer's at your garden center. Never spray anything during hot, windy weather, evening is good. You might apply a liberal amount of bone meal and greensand throughout the dripline of the trees, it will provide phosphorous and potassium for next year's crop, as it will help with blossoming and fruit development.

* * * *

Dave
Even my growlights are getting restless!

fruit trees, sometimes will not make fruit if last years load was too many.. and it might just be resting this year..
Or if last year was too dry, stress on the tree can also have the same affect..
give it a fruit spike, and water well this year.. next year you should see more.

With all Fruit trees you may need to thin them if they are bearing too much fruit- a good rule would be one apple or fruit at 6inchs apart.. more then that they need to be thinned out- or you may see none or very little the next year.

Just be sure you use the spikes for Fruit trees ( I like them the best) and I use them 3 times a year for a healthy tree and fruits.

Also when it was in bloom, did you have a late frost that could had killed the blooms this spring?
If you have late frost in your area- try this out
hang bottles of water in the trees branches, ( if you have a big tree, use gal milk plastic containers, be sure to cut the top off and use a punch to make holes so you can string it up in the branches..
If it is smaller just use the plastic pop bottles cut in the same manner as the Gal plastic containers.

It sounds nuts, but it works by drawing the frost from the tree into the water.

* * * *
Christina