Dawn, what insecticide you use to kill gypsy moths. Is the insecticide labeled for fruit tree. If not, you should not eat the fruit. if the insecticide is good to use on fruit tree, spray a month ago is too long to protect your tree. Good cover spray work about 10-14 days depending on how much rain you get. Also, to help spray stay on longer, you need to use sticker like Bonide Turbo mixing in with the spray. There is a good chance that insects Oriental Fruit Moth or Plum Curculio punctured the skin of those peaches to lay eggs which will hatch to be larvae that move inside ppeaches to feed. Fruit will drop and when you cut them open, you will see tumpnnels or even worms inside. Check those fruit that have clear gel carefully to see if there is tiny holes on the area. If so, pick them off. Throw them out with trash. Do not let fruit lie around under the tree or compost it. You will help their life cycle that way. Spray with insecticide labeled for peach trees.

BK: My first guess, and nothing more, is hail. Second deer?? Any chance you had a hail storm?

Lilacs: Your peaches have been visited by the oriental fruit moth. The damage probably occurred some time ago, but is now becoming easily visible due to the oozing of pectin. The peaches may continue to ripen (although some may fall), but when you take them down the affected peaches will be seriously deteriorated around the pit area, and some larvae may be present. I don't know how long you have been growing peaches, or the severity of OFM pressures in your particular part of Colorado. In my area of Northern Virginia OFM is a constant presence from early spring right through midsummer. I either have to spray in a timely manner, beginning right at the fruit thinning stage, or bag the peaches in shoe store "footies", or both. I would expect OFM pressure to be less in the dryer, higher climate of Colorado, but in a given year it could be pretty bad. Weather has not caused your peach problems, nor is it a disease. It's a very nasty moth. Don Yellman, Great Falls, VA

Yes most time they kill tree I select another are leave that one another if have room borer are bad on peach-trees it may recover it take years. Two thing you got case to get replacement for that tree. I f bought tree at big box store you pull up take back and exchange it. If got from nursery go there look at what have first you may see more what you have do a little investigate don't tell what doing if don't have any problem with there stock then tell store them, may just give tree are have to bring tree in. If don't have little round holes maybe canker and nursery want want plant back..