Observation: Photinus pyralis
Primary Observer:
Mary Patterson
Event Date:
2026-07-23
Status:
Unreviewed
Survey
Site Name:
Mill Creek Falls Nature Preserve #3
Province/State:
Pennsylvania
Event Date:
2026-07-23
Time of Day:
Night-Time
Start Time:
20:51
End Time:
21:45
Number of Observers:
2
Primary Observer:
Mary Patterson
Additional Observers:
Ross Patterson
target_species_genus:
unknown
target_species_species:
unknown
Location and Habitat
Location Accuracy (meters):
25-50
Habitat Type:
Grassland/Meadow - Meadow, open, grasses dominant
Habitat Type Notes:
power line cut
Elevation (meters):
155
Area Searched (hectares):
2
Artificial Light Sources
Vehicles: Yes
Street Lights: No
Buildings: No
Street Lights: No
Buildings: No
Artificial Light Types
Sky Glow (diffuse illumination in the sky): No
Light Trespass (light cast on surfaces beyond its intended target): No
Glare (bright light causing visual discomfort): No
Light Trespass (light cast on surfaces beyond its intended target): No
Glare (bright light causing visual discomfort): No
Artificial Light Notes:
Observation
Observation Type:
With Flash Data
Number Observed:
2-10
genus:
photinus
Species:
pyralis
Observation Notes:
Specimen Voucher Number:
Flash Behavior
First Flash Time:
21:00
Last Flash Time:
21:40
First Flash Temp (F):
72
Last Flash Temp (F):
62
Flashes in Pattern:
1
Flash Color:
Yellow
Flash Pattern Period:
long, not exhibiting a pattern, more intermitent
Flash Duration:
1
Flash Interval:
long, est 10-15 seconds
Male Height Zone:
Moderate (3-8 ft)
Flash Location:
above meadow and edge habitat. This night there were very few species in comparison to other nights. Quite lower humidity and lower temp, the start temp this night was what our end temp had been on other nights. Temp dropped significantly during that hour of obeservation.
Instead of the traditional smooth J shape there was a bit of a zig zag move at end of flash
