Observation: Pyractomena dispersa
Primary Observer:
Candace Fallon
Event Date:
2025-07-02
Status:
Unreviewed
Survey
Site Name:
Billingsley Creek
Province/State:
Idaho
Event Date:
2025-07-02
Time of Day:
Night-Time
Start Time:
21:40
End Time:
23:08
Number of Observers:
2
Primary Observer:
Candace Fallon
Additional Observers:
Emilie Blevins
Target Species Genus:
Pyractomena
Target Species Species:
dispersa
Location and Habitat
Location Accuracy (meters):
0-25
Habitat Type:
Riparian - Areas Along lake or stream
Habitat Type Notes:
Riparian area along Billingsley Creek: bulrush, showy milkweed, grasses, nettle, juncus, Russian olive. Multiple springs feed into the creek from the north. The habitat in which the fireflies were found (tall bulrush and nettle along open water) is unlike the described habitat for this species elsewhere in the western US.
Elevation (meters):
904
Area Searched (hectares):
11
Artificial Light Sources
Vehicles: Yes
Street Lights: No
Buildings: Yes
Street Lights: No
Buildings: Yes
Artificial Light Types
Sky Glow (diffuse illumination in the sky): Yes
Light Trespass (light cast on surfaces beyond its intended target): No
Glare (bright light causing visual discomfort): Yes
Light Trespass (light cast on surfaces beyond its intended target): No
Glare (bright light causing visual discomfort): Yes
Artificial Light Notes:
Sky glow on horizon in direction of Hagerman (south) as well as glare from passing vehicles on the road and lights from buildings on the horizon.
Observation
Observation Type:
Flashing
Number Observed:
2-10
Genus:
Pyractomena
Species:
dispersa
Observation Notes:
Approximately 10 individuals observed flashing. Because we got to the area where we saw them later in the evening, we suspect there were more individuals out earlier, and we were seeing the tail end of their activity period (this species typically only displays for an hour or two).
Specimen Voucher Number:
Lampy-001-2025-XS, Lampy-002-2025-XS
Flash Behavior
First Flash Time:
22:35
Last Flash Time:
23:08
First Flash Temp (F):
74.8
Last Flash Temp (F):
74.5
Flashes in Pattern:
1
Flash Color:
Yellow
Flash Pattern Period:
<1 second
Flash Duration:
<1 second
Flash Interval:
Not recorded
Male Height Zone:
Moderate (3-8 ft)
Flash Location:
Males flashing just above bulrushes along the edge of Billingsley Creek, near the road and boat ramp.
Male Flash Behavior:
Single quivering flash repeated every 1-2 seconds; flash appears to fizzle out at the end. Individuals often flew with a small swoop upwards just prior to flashing.
Female Flash Behavior:
Single flashes from 1-2 individuals (suspected but not confirmed to be females) were observed from lower perched locations on the bulrushes and other vegetation.
