Fwd: California Tortoiseshell

[Carolyn King]

Just passing on this exciting sighting from TEA member Peter Waycik in Eastern Ontario.

Carolyn King

Toronto Entomologists' Association

---------- Forwarded message ---------
From: Peter Waycik <way...@gmail.com>
Date: Tue, 29 Jul 2025 at 14:21
Subject: California Tortoiseshell

I encountered this tortoiseshell on Howe Island today and since it didn't quite match a Compton, I asked Bruce Ripley who (excitedly) suggested it is probably a California Tortoiseshell.

https://inaturalist.ca/observations/302149665

Peter Waycik

[Carolyn King]

There may be other sightings of California Tortoiseshell around Ontario, as they sometimes have mass migrations. We had three sightings of them in Ontario in 2022.

There was a report from Nelson, B.C. 2 weeks ago:

An Irruption Year for California Tortoiseshells?

Today, a California Tortoiseshell visited our property. We've had them in prior years, but this was the first one to visit our property in 2025. However, on several butterfly outings this year, we've encountered dozens and dozens of them. Up at Kootenay Pass, along the rail trail south of Nelson and even along the Whitewater Ski Hill Road. I've never seen so many California Tortoiseshells. Bob Pyle and Caitlin Labar in their book Butterflies of the Pacific Northwest talk about this species' propensity every now and then for dramatic irruptions. It's great to see.

Posted on July 14, 2025