Many of the crawling pest overwinter in old fallen fruit, so the problem tends to multiply. If you had a few
chickens, they would have a good time cleaning up, eating the apples, larvae and all, plus any other bugs they could find.
The makers of the Tanglefoot goo also have a tree banding material that you wrap around the trunk and then spread the goo on. When it's loaded with dead caterpillers, you just peel it off and apply another. If your problem is really bad, place two bands around the trunk, a few inches apart. Then, when the lower band is loaded and the latecomers are just crawling over the bodies of their friends (laughing, I'm sure), they hit the upper band and they're goners.
If you live anywhere within reach of Olympia, you might visit Black Lake Organics on Black Lake Blvd, Oly, about 2.5 miles south of Hwy. 101.
Sue