Attached you will find a photograph of a Pear from one of my trees. This has been happening to both Asian and European pears. They have been half eaten, then left on the tree. It appears to be eaten to the core and then left. I thought it was being eaten from the inside out but I've found other pears with just a small amount eaten on them. So far I've found no insect or other animal doing the damage.

Some pears also have little black holes drilled into them but upon cutting them open I haven't seen any maggots inside. The weather has been just right for moth, rainy, cold and windy, I haven't seen any moths around though. The only insect I've seen on any pears is the pear shaped clover beetle.

Anyone know what could be damaging the pears and how to prevent it? I have never sprayed my trees, I prefer to find other methods to deal with pests. Thank you for any help you can provide.