Native pear tree? I don't think there are pears that are native to the U.S. There are native plums, cherries and crabapples.

As for dealing with the bugs, try first just blasting the leaves with a hose. Repeat daily (even twice a day).

But leaf chomping is usually not a fatal activity. They should be fine.

So sorry, I meant they're native plum trees. We lost our last plum tree, a Santa Rosa, to black knot. So we thought let's try native species. And yes we do have two pear trees in front yard, no insect damage so far, thank goodness. Thanks for posting!

I hadn't thought about planting native plums. if you have add'l information, please share. we are preparing to plant two plums (for cross-pollination) this fall, along with two montmonrency cherries.

Prunus americana is a native plum. There is also:

Prunus alleghaniensis (not as common)
Prunus angustifolia
Prunus munsoniana

Here is a link that might be useful: Visit the Prunus page on the USDA database