Observation: Unknown
Primary Observer:
Elizabeth Harvey
Event Date:
2025-06-24
Status:
Unverified
Survey
Site Name:
Undisclosed
Province/State:
Illinois
Event Date:
2025-06-24
Time of Day:
Night-Time
Start Time:
20:35
End Time:
21:25
Number of Observers:
2
Primary Observer:
Elizabeth Harvey
Additional Observers:
Matt Harvey
target_species_genus:
unknown
target_species_species:
unknown
Location and Habitat
Location Accuracy (meters):
25-50
Habitat Type:
Developed - Sub/urban areas; parks/gardens
Habitat Type Notes:
Elevation (meters):
580
Area Searched (hectares):
Artificial Light Sources
Vehicles: Yes
Street Lights: Yes
Buildings: Yes
Backs up to a back road with farmland beyond on one side
Street Lights: Yes
Buildings: Yes
Backs up to a back road with farmland beyond on one side
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:
Backyard string lights
Observation
Observation Type:
With Flash Data
Number Observed:
11-50
genus:
unknown
Species:
unknown
Observation Notes:
Specimen Voucher Number:
Flash Behavior
First Flash Time:
20:33
Last Flash Time:
21:17
First Flash Temp (F):
81
Last Flash Temp (F):
79
Flashes in Pattern:
3
Flash Color:
Yellow
Flash Pattern Period:
60
Flash Duration:
2
Flash Interval:
15
Male Height Zone:
Moderate (3-8 ft)
Flash Location:
Saw a cluster of maybe 10, about 40ft away in a more shadowed part of the yard. But also a few stragglers bopping around the patio, connected garden, and a few closer to the road on the other side.
Male Flash Behavior:
Female Flash Behavior:
1 thought on “Observation: Unknown”
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Thank you for submitting this firefly observation! Without a photo of the firefly, it is tricky to reach a species identification, but it is great to know that this site supports fireflies! Based on the habitat and location, Photinus pyralis seems like a likely option.
A note about flash pattern terminology, for next firefly season:
“Flash pattern period” refers to the number of seconds between the start of a flash pattern and the start of the next repetition of that flash pattern. For example, the big dipper firefly (Photinus pyralis) typically has a flash pattern period of 5-7 seconds.
“Flash duration” is how long each flash lasts. Usually this is too fast to measure accurately, but you can estimate whether it is more or less than 0.5 seconds, you can enter “not recorded,” or you can do a verbal description (such as “very brief”).
“Flash interval” refers to the time between the end of one flash and the beginning of the next. In species with single flash patterns and short flash durations, this is basically the same as “flash pattern period,” just a little shorter.