InsectNet forum

Here are some Colias I collected recently.



Left upper is Colias occidentalis from Siskiyou County California

Left lower is Colias alexandra and on right Colias occidentalis from Elmore County Idaho.

Here is a terrible cellphone pic from the Elmore County Idaho locality.



Note the two species of Colias in the middle but I couldn't get too close without disturbing the swarm of Mormon crickets.

I am unfamiliar with Western Colias.

Are any of these particularly difficult to find in the field ?

I've got a few Colias, I have found that they're locally common at times. Last season we spent a few hours near Detroit Lake in OR and
one or two would fly by at a time, seems like there was always one flittering about. Just like real estate, location and timing.
That being said- finding that spot takes some luck in any event,

All of those species are resonably common if you find the right spot at the right time. I've collected all of them at times during only three short trips to the Rockies.

The ones on the right look more like C. christina than C. occidentalis to me.

bobw wrote: Thu Jul 13, 2023 5:32 pm The ones on the right look more like C. christina than C. occidentalis to me.

Ones on the right are subspecies resplendens which has sometimes been considered the same as pseudochristina. I agree they look more like christina to me as well.

I've looked at some of my series, and there is a particularly orange form of occidentalis pseudochristina in Idaho, although I only have them from Franklin co. (resplendens is purely a synonym, and another of those ridiculous Hammond & McCorkle names). C. christina sacajawea nearly always has much more yellow basally, so on reflection, it probably is occidentalis.