Re: Sulphur ID Help
This is a nice shot of a female Orange Sulphur (Alfalfa Butterfly) Colias eurytheme, Kay. Note the orange flush, which in most of Oregon, only this species normally has. You can tell it's a female by the fenestration (window-spots in the black margin on the upper side, which shows through to the underside in this view. It also shows the brown "eurytheme spots" around the hindwing just in from the edge, though they are very light on this one. This is the only species of sulphur you are likely to see in the western Oregon lowlands, with its numbers increasing in late summer.
The Western Sulphur (C. occidentalis) is largely Cascadian, not a valley butterfly, and it flies earlier. You'll find pretty good shots of both of these in our PNW field guide and on Butterflies of America website.
On 2022-08-03 2:16 pm, Kay Carter wrote: