Notice: Below is a list of 0 important links included on this page.
Please note that while screen readers have made significant strides, they may still lack full support for optimal web accessibility.
Observation: Photinus pyralis
Primary Observer:
Matthew Moore
Event Date:
2025-06-11
Status:
Unverified
Survey
Site Name:
Home Dixon IL
Province/State:
Illinois
Event Date:
2025-06-11
Time of Day:
Night-Time
Start Time:
20:00
End Time:
21:12
Number of Observers:
1
Primary Observer:
Matthew Moore
Additional Observers:
Target Species Genus:
Target Species Species:
Location and Habitat
Location Accuracy (meters):
0-25
Habitat Type:
Developed - Sub/urban areas; parks/gardens
Habitat Type Notes:
Back yard, large grass yard with garden. Organic, no chemicals. Less than 500 feet from Rock River.
Elevation (meters):
152
Area Searched (hectares):
0.1
Artificial Light Sources
Vehicles: No
Street Lights: No
Buildings: No
Street Lights: No
Buildings: No
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): 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:
Flashing
Number Observed:
1
Genus:
Photinus
Species:
pyralis
Observation Notes:
Large size for species. Single flash followed by trailing glow. Firefly light Yellow in color. Back yard lawn, organic, no pesticides.
Specimen Voucher Number:
Flash Behavior
First Flash Time:
20:25
Last Flash Time:
20:30
First Flash Temp (F):
83
Last Flash Temp (F):
82
Flashes in Pattern:
1
Flash Color:
Yellow
Flash Pattern Period:
2
Flash Duration:
2
Flash Interval:
10
Male Height Zone:
Moderate (3-8 ft)
Flash Location:
Single element of tail
Male Flash Behavior:
Female Flash Behavior:
Flash in single element. Single yellow Flash with trailing glow. 4 ft off ground at first sight. Stayed low. Flash every 8 to 10 seconds until entering brush and tree line.
1 thought on “Observation: Photinus pyralis”
Leave a Comment
You must be logged in to post a comment.
Thanks for submitting this firefly observation! I agree that Photinus pyralis seems like the best match, though a photo would help to rule out other species (I know that’s not always possible!).
Flash pattern terminology can be confusing, so here is a link to a brief video explanation of what exactly these timings refer to: https://youtu.be/cZCcPKq79SM?si=QBHiJIiyHUJvEQtB&t=1171.