Why is my cherry fruit rotting? aphids? too wet? disease? some aren't but most are and they are...

aphids? too wet? disease? some aren't but most are and they are young fruit. the tree seem relatively happy with lots of untried growth,some black aphids that I started cutting off today. but the latest fruit is falling without even maturing and i want to know why and what i can do to prevent this.
Landscaping/mulching/weeds?
Answers:    What type of spray have you be using? All fruit trees need to be sprayed from the time BEFORE they bud 'til the week you harvest. If you haven't sprayed anything, continue 'til next year and get on the proper spraying agenda. Usually every 2 weeks.