Unfortunately there is no way to tell how many more -- it seems like your area has a lot. If your pears don't show any evidence of damage yet, you can try bagging them (buy cheap sandwich bags, cut off a lower corner so moisture can escape, then fasten one bag over each pear -- close the bag right up to the stem).

There are insecticides that can be used also but I don't know if it is the wrong time to try those (it is too late in my area). Hopefully one of the more expert fruit growers will answer.