Man- all that sucks. The girdled tree may be ok. I’d spray it monthly with fungicide & insecticide. Heck- same with jap beetles. It’s like creating a wound on ur skin.... chewed stuff or bugs- it’s an opening bugs and disease can get into. A totally girdled tree MIGHT make it. It wasn’t a lot of area up/down so that helps.
On jap beetles - are trees still alive? Like, green leaves? Can u or have u sprayed them? Keep at it!!!
K- in general.... here’s how I describe Apple trees in Iowa..... to bottom line it.... they just need more care than other states. They need more sprayings (monthly) & need ideal pics on planting sites. Monthly sprayings for bugs, fungus, mildew, etc. & same with weeds... mulch with limestone for example & keep weeds toast. Screen or latex with pepper - ONLY way to protect trunks!!!!!! .....
Sprayings take 2 mins a tree. Maybe. It’s not that hard but yes, they need care!!! The right varieties & root stock are critical as well!!! Just like a food plot or crop.... let’s say “CORN” for example..... it needs 2 sprayings most the time with 3+ herbicides. It needs fertility dialed in just right. The genetics allow it to deal with many of nature’s obstacles. Even when done perfect- pests, weeds, critters can still be an issue. Corn needs TLC (any crop) & apple trees are no different. Iowa farmers just “make it look easy” but it’s not. It’s billions in genetic research & pesticide development & then it’s a gazillion dollars & work in land, equipment, knowledge & timing to make even that successful.
So- plant right varieties & rootstock. Avoid common mistakes (all in this thread), spray a million options & at different times in season (& yes, there’s tons of responsible pesticide options u can find, some of which are even organic) religiously for first 5 years &
Likely still 2-3 times after that. Weed control, watering if drought, all those things. I know all this sounds hard but it’s not. It’s like anything else: do the research & then keep up with taking care of trees with a relatively small amount of work ongoing. They can be very successful done right!!!!