Answers

The new ridge vent should have the bug/snow/rain barrier integrated into the venting system. There are probably many other areas in the attic into which "bugs" could enter, but attics do not typically make the best habitats since the temperatures can be extreme and there is no "relatively nearby" source of water for them to survive. The "integrated mesh" is more for helping to prevent wind blown rain and snow from entering the attic space and settling on whatevr lies below.

The pictures were very helpful - thank you.  It looks like only the first ply/layer came apart which is not optimal but minimal risk for coming apart allowing the ridge vent to come off especially if they used every nail hole during installation. The bug barrier appears to be intact and the breakage of the plywood would not interfere with that.

That would really be a question for the roofer on the split wood.  As for a bug barrier; that would be a question for a pest control company but that has never been a significant issue in our experience.  It is very important that there be adequate ventilation in all attic spaces that are not heated.

Many pests like raccoons, squirrels or mice crawl into the house through the attic and crawl spaces if there are no barriers to prevent them from getting in. They may have mites, fleas, bugs and other pests, which may infest your home. Therefore it is necessary to implant a proper barrier and maintain a proper ventilation in our attics. The pest exterminator New Jersey professionals may also be consulted for the same to get better suggestions.