Observation: Photinus pyralis
Primary Observer:
Ellie Shultz
Event Date:
2026-08-07
Status:
Unreviewed
Survey
Site Name:
Clear Lake Nature Preserve
Province/State:
Indiana
Event Date:
2026-08-07
Time of Day:
Night-Time
Start Time:
20:50
End Time:
21:45
Number of Observers:
1
Primary Observer:
Ellie Shultz
Additional Observers:
NA
target_species_genus:
photinus
target_species_species:
pyralis
Location and Habitat
Location Accuracy (meters):
0-25
Habitat Type:
Grassland/Meadow - Meadow, open, grasses dominant
Habitat Type Notes:
The habitat type also included woodland/forest with trees dominant and in the overstory. I was stationed on the edge of the forest where the prairie began. The prairie included a wide variety of native wildflowers and grasses.
Elevation (meters):
323
Area Searched (hectares):
50
Artificial Light Sources
Vehicles: No
Street Lights: No
Buildings: Yes
Street Lights: No
Buildings: Yes
Artificial Light Types
Sky Glow (diffuse illumination in the sky): No
Light Trespass (light cast on surfaces beyond its intended target): Yes
Glare (bright light causing visual discomfort): No
Light Trespass (light cast on surfaces beyond its intended target): Yes
Glare (bright light causing visual discomfort): No
Artificial Light Notes:
There were some houses on the other side of the prairie that had bright outdoor lights.
Observation
Observation Type:
With Flash Data
Number Observed:
50+
genus:
photinus
Species:
pyralis
Observation Notes:
Once captured in the bag, this firefly emitted a drop of liquid.
Specimen Voucher Number:
Flash Behavior
First Flash Time:
20:55
Last Flash Time:
21:45
First Flash Temp (F):
76
Last Flash Temp (F):
74
Flashes in Pattern:
1
Flash Color:
Yellow
Flash Pattern Period:
5.6
Flash Duration:
.6
Flash Interval:
5
Male Height Zone:
Low (0-3 ft), Moderate (3-8 ft)
Flash Location:
The firefly activity started in the darker forest about 10 minutes before it began in the open prairie. Activity in the forest started at 8:55 and decreased noticeably about 25 minutes after it began, at 9:20. Activity in the prairie started at 9:05 and decreased noticeably about 25 minutes after it began, at 9:30. There were still some fireflies flashing in the forest and prairie when I left at 9:45, but not nearly as many.
Flash height was 0-3 feet at first, but got higher as time went on. About 15 minutes after they started, the height was more like 3-6 feet. Once the fireflies started flashing in the prairie, I noticed the same thing: low flash height at first before rising.
