Continuing with the subject of early year moths, the Egira genus shares the same Orthosiini tribe as Orthosia. I’ve often struggled to tell simplex and crucialis apart for specific individuals.

Egira crucialis

Egira simplex

Both are spring moths, showing up around the same time, flying Mar-June.

So what traits are diagnostic?

Perhaps 9 times out of 10, I find crucialis and simplex pretty easy to tell apart. There’s a range of small differences: crucialis‘s scales often have a feathery/powdery look to them compared to simplex. They seem to hold their wings slightly differently: crucialis can appear more tubular, keeping its wings folded closer over the body while simplex holds them flatter to the surface. Simplex generally looks a bit scruffier and typically has more black on the wings – especially medially. E. crucialis often has more red in its reniform spot.

But none of these characteristics are definitive in of themselves. Dave Holden shared the following slide in a recent BC Leps meeting. The most consistent differentiator was the strength of the dot on simplex‘s hindwings. Great to know, but unfortunately it’s seldom a trait you’d likely to see in the field.

The following picture is from Oliver, BC, taken early April 2024. Both were quite a bit greyer than the specimens Ive been seeing recently on Bowen, but it was a nice juxtaposition of the two species. Egira crucialis on the left, Egira simplex on the right. I think.

I rather suspect that a lot of scruffier crucialis are mis-identified as simplex.