My pears are just starting to grow, but have been savaged by what at first looks like rot but under the microscope it appears to be these little upside-down pear shaped grubs (or maybe mites) who seem to be towing small orange eggs(?) around and placing them on the periphery of the rotten spots. The inner area of the rot looks fiberous and black.
It's pretty hard with my setup to catch one of these grubs on camera, but I will share a not so great picture of the fruit damage.
I also noticed numerous bumps on leaves, which may be related. That's the second picture, and the third is a 10x magnification.