Red sweetgum leaves in Oakland neighborhood, 20 October 2026 (photo by Kate St. John)

26 October 2026

Fall leaf color has been weak this month. The maples turned red early but their leaves were blown off in strong winds about a week ago. In the city’s urban heat island, the oaks have not changed yet so it was a relief to find bright red sweetgum leaves in Oakland (at top).

Leaves were still green in Schenley Park last Friday, though the sun rays were a nice touch.

Sun rays at Schenley Park, 23 Oct 2026 (photo by Kate St. John)

Insects are getting ready for winter. Last week I found a caterpillar heading down the curb into the street. Google Lens said it’s a yellow-striped armyworm (Spodoptera ornithogalli), a food generalist that pupates underground. This one was in for a rude awakening when it found asphalt beneath the fallen leaves. In farming country this caterpillar is a pest because it eats crops.

Yellow-striped armyworm caterpillar, Bayard Street in Pittsburgh, 21 Oct 2026 (photo by Kate St. John)

On Friday in Schenley I also saw this very white cocoon attached flush to a stem along its length (side view at right). Do any of you know what this is? Please leave a message.

Mystery cocoon in Schenley Park, 23 Oct 2026 (photo by Kate St John)

This month’s surprise has been an influx of pine siskins (Spinus pinus) in western Pennsylvania. Based on my reading of the Winter Finch Forecast 2026-2027, I didn’t expect them to reach Allegheny County. Yesterday I saw them at the Hartwood Acres Mansion hemlocks. Steve Gosser got an excellent photo.

Pine siskin, Hartwood Acres Mansion hemlocks, 25 October 2026 (photo by Steve Gosser)