This is the webbing of fall webworm.  There is a spring-summer generation and a fall generation.  This year the spring one is larger than usual, but it is a native insect and has limited impact on plants, plus it is a great source of food for wildlife.  We recommend leaving it alone or breaking it up to let the birds eat the caterpillars, but since there are so many, you might want to hand remove them or prune them out.  Here is more about them: https://extension.umd.edu/hgic/fall-webworm-trees

ECN