Some type scale. Squish them if not too many. Spray dormant oil in winter. Mine are easily killed by Malthion or other insecticides but some are not. The big fat ones are adults. At times there will be crawlers, the younger types that move around. All need killing. Spray the dormant oil each winter and you can limit or eliminate the issue.

Laagarden: You have serious borer injury at the base of your tree. Get out to Wal-Mart or wherever else you buy your stuff, and find a box of mothballs. Push a dozen or so of them into the soil close to the trunk of the tree. The mothballs will kill the borers and prevent them from recurring, although the damage to your tree may be permanent. Renew the mothballs every season, and you will not see this damage again. Borers arrive at trees as moths, and if mothballs are there they will leave you alone. Mothballs do not damage the tree or anything else, regardless of what you may read on the internet. Don Yellman, Great Falls, VA

Sabrina, The best advice that I should give to you is contact your local agricultural extension office. This/these network(s) of local offices are usually connected with a state University or College with agricultural programs with experts who know your local area (and related diseases/pests) the best. Additionally, I have never been charged for their services. I'm not sure where you live in CA, but this is one statewide network that may be helpful(http://ucanr.org/), its the UC Davis center hub for ag extension offices. California has excellent resources in that the agricultural industry is huge, and many experts are in the area. What I did when I suspected fire blight on a new tree is take the best pics that I could. Then I suggest that you call up the ag office and speak with a specialist, master gardener, etc and if needed, send the pictures to him/her via web. I thik that even in certain special circumstances they send people out to look at trees. I think/hope this approach will end the guesswork for you as it did for me. Best of luck. http://ucanr.org/ce.cfm or- Type this into Google: university of california davis agricultural extension office

Several insects will get the same oozing of pectin response in peaches and they don't all respond to the same spray regimen. You do need to know if it's from OFM or PC on one hand or stink bugs or tarnished plant bug on the other as the latter couple are more difficult to control with standard spray options. My attitude about peaches is as long as they are giving you vigorous shoot growth as your picture suggests is happening, they are useful as they still produce as good a fruit as ever. Nothing wrong with having backups, and peach trees take very little time to replace, but no need to cut a productive tree down because its trunk is suffering from canker. Peaches benefit from having a lot of grass and weed free soil during the first half of the growing season- they don't compete well with weeds are other trees. I like at least a 5' diameter mulched ring for them.