Ryan, In MA, I say we need to spray our peach trees for both diseases and insects. Common diseases for peach are Peach Leave Curl, bacteria spot (also called shot hole), peach scab and brown rot. Common insects are Plum Curculio, Oriental Fruit Moth and coddling moth. Some people go more organic, some prefer chemicals since the latter tend to be more effective. I am in between. When I can use less chemicals, I do. For me, before bud break (mid March), I spray copper hydroxide (the brand I use is called Kocide 3000). I add Spreader/Sticker in the mix for copper stay on better/longer. It help with PLC and shot hole. I use sulfur spray for scab. Sulfur is not as effective as fungicide like chlorothalonil (brand name Daconil) or Captan. Captan is also help prevent brown rot. Brown rot is not a serious issue for me yet (it's coming, I know it) so I have not used anything. A week after petal fall, I spray Triazicide Once and Done for insect control. Then, I used footsies soaked in kaolin clay called Surround. It works if timing is right. If you don't want to put footsies on your peaches, you can spray Once and Done a few more times 10-14 days apart depending on rain and pest pressure. I am considering spraying Surround instead of using footsies this year. It will coat the fruit and prevent insect from damaging it. Putting footsies on 100+ peaches was not easy. Hope this help.

Thanks larry gene. yeah, some people meaning smart people. Guess I ain't one of them kind. Just sprayed the heck out of my plants. Guess I'll find out in a week or two whether I burned 'em, and in few months whether I got the critters. One piece of advice I heard that's worth repeating here for anyone who hasn't heard it: when you're spraying something that kills by smothering, it's best NOT to spray in the heat of the day. Here in Southern California, our days, even in winter, can get upwards of 80 degrees (don't they wish they had winters like that in the Midwest and the East!). So, potentially, Golden Pest Spray Oil could damage the leaves if I were to spray it mid-day. Just a heads up for anyone using this product, or a similar type oil spray. Of course, if you're plant is still dormant, you won't have to worry about burning the leaves 'cause there won't be any! Hope this helps, ThisBud4U

These are bagworms. The easiest thing to do is take a grocery bag and a pair of scissors ... and cut the bags off the tree, depositing them in the grocery bag for disposal. If your tree is large ... or if it is your preference, you might try a insecticide spray early next spring ... ... "You can control bagworms by hand-picking them from infested plants during the winter or before the eggs hatch in the spring," says Dr. Patricia Cobb, an entomologist with the Alabama Cooperative Extension System. Cobb suggests using chemicals to control bagworms only as a last resort. "Chemicals, such as Orthene Turf, can kill bagworms if applied in May or June while the caterpillars are still small," says Cobb. SOURCE: DR. PATRICIA P. COBB, Extension entomologist , Alabama Cooperative Extension System

I use Ortho Orthenex. It's a Systemic insecticide. I buy it down at the local Ace Hardware store. It comes in a green spray can. Here is a link that might be useful: Backyard Bogs (The Natural Alternative)