On a warm night, the speaker notices insects still making their sounds, chirping and trilling "out of sheer habit," as if they're carrying on after the season has stopped needing them. The opening image is odd and a little eerie: insects "of smoke," slick as silkworms, weaving "winding sheets," which are burial shrouds. The whole scene feels like something ending, but quietly, without fuss.
Then the poem turns to a small, strange moment from the day. A dead leaf, hanging on a dead tree it doesn't even belong to, seems to wave at the speaker. The speaker waves back, and that last line is the key. It's funny and tender at once.
The mood is wry, calm and gently melancholy. The speaker doesn't panic about death or decline. Instead, they greet it with good humor, treating a dying world as company worth acknowledging, and finding a little grace in that exchange.