Δευτέρα Moth

I’m going to keep the ball rolling with this series and try to make it more regular. I will also focus on highlighting a new species each week from the massive collections here at the California Academy of Sciences. This should give me enough material for… at least a few hundred years.

Grammia edwardsii (Erebidae: Arctiinae)

This week’s specimen is the tiger moth Grammia edwardsii. Up until a few years ago this family of moths was considered separate from the Noctuidae – but recent molecular and morphological analysis shows that it is in fact a Noctuid. The family Erebidae was pulled out from within the Noctuidae and the Arctiidae were placed therein, turning them into the subfamily Arctiinae. OK boring taxonomy out of the way – all in all, it’s a beautiful moth and almost nothing is known about it. This specimen was collected in San Francisco in 1904 – in fact almost all specimens known of this species were collected in the city around the turn of the century. While this moth looks very similar to the abundant and widespread Grammia ornata, close analysis of the eyes, wing shape and antennae maintain that this is actually a separate species. I believe the last specimen was collected around the 1920’s and it hasn’t been seen since. It is likely and unfortunate that this moth may have become extinct over the course of the last 100 years of development of the SF Bay region. Grammia, and Arctiinae in general, are not known for high levels of host specificity; they tend to be like little cows and feed on almost anything in their path. So it remains puzzling why this moth wouldn’t have habitat today, even in a city so heavily disturbed. Perhaps this moth specialized in the salt marsh areas surrounding the bay – which have all since been wiped out due to landfill for real-estate (1/3 of the entire bay was lost to fill). Or perhaps this moth remains with us even today but is never collected because it is an evasive day flying species. I always keep my eye out in the park in spring for a small orange blur…