Can anyone here identify the problem on these cherry tree leaf photos?

[grlight]

Howdy All!

I have this cherry tree that is sick. Please somebody id this. I cannot find anything in Google images when running various searches.
The tan blotches in the green leaf are actually translucent, almost like thin parchment paper. The yellowed dead leaf is similar but is the end result. We are going to lose this tree if we don't get it figured out soon.

It is a 2 year old Stella Cherry. When all blooms had dropped off, we treated it for an aphid infestation, but not yet a bad one. Used Monterey Fruit Tree & Vegetable Systemic Soil Drench about a week plus ago. Careful to follow instructions so the correct quantity in the correct manner. Aphid problem is gone. But this unknown issue has begun! Other fruit trees treated for same problem at the same time have no aphids and are healthy and thriving.

Thank you in advance everybody!

 

[NigelJ]

Could be Cherry slugworm see here https://www.rhs.org.uk/biodiversity/pear-and-cherry-slugworm The damage is quite distinctive

 

[grlight]

Could be Cherry slugworm see here https://www.rhs.org.uk/biodiversity/pear-and-cherry-slugworm The damage is quite distinctive

Thank you! :hurray: After your reply I began searching the tree and lo & behold, I found a couple in their larval stage. I used the Monterey systemic a week ago. so should be OK, "God willing.