Found 7/1/2023 on laundry room floor in house; photos taken 2 days later in kitchen. Neighborhood mixed oak/loblolly pine.
Looks like a beetle larvae, glow lasted for about a half an hour.
Length 10 mm. A common Ellychnia in the northwest.
Crossposted to the Firefly Atlas: https://www.fireflyatlas.org/firefly_observation/36867
This larva was found by its green glow crawling gravel and cobble in the creek bed of Limpia Creek at about 10:50 PM. We suspect that it is Photuris flavicollis because the coloration is very different from versicolor complex Photuris larvae and this is a known locality for P. flavicollis, but I don't think the larvae of P. flavicollis have been described.
Photo 5 shows the bioluminescent lanterns after the specimen had been in the fridge/freezer for about 6 hours.
Photo 6 shows the microhabitat where the larva was found: in the damp pebbles on a sloping part of the dry main channel, under cottonwood trees.
Adults were observed displaying from around 7 PM to 7:30 PM. Flash pattern details were not recorded for this individual, adult males in the area were emitting single flashes at intervals/periods of 3-4 seconds at a temperature of about 80-85 degrees F. Most photos were taken after the individual had chilled in a freezer for about an hour, so there is some condensation on it.
B. w. wickershamorum