Observation notes: I first noticed the moth at about 8 am. At 4 pm, it hadn't moved in the slightest. Went for the incredibly scientific and complicated process known colloquially as "poking it with a stick." Well, it didn't want to move. Thought it might be dead, but it seemed to stand up taller. I tried it again, and it made a pass at my face. Twice. Then flew off and landed somewhere else nearby.
Another note, this thing was big. I've seen bigger, but only in places like Central America and Arizona. Here in Northern California? Nothing. Probably a good 6 inches long.
Verified by: Josiah Gilbert
Verified date: July 25, 2014
Coordinator notes: One of the biggest (if not the biggest) moths recorded in Napa county is the Polyphemus moth (Antheraea polyphemus), see here http://www.butterfliesandmoths.org/species/Antheraea-polyphemus. To see some other large moth species which occur in your area, take a look at the wild silkmoths and Sphinx moths on BAMONA's regional checklist for Napa County here: http://www.butterfliesandmoths.org/checklists?species_type=All&tid=402.