Observation: Photinus marginellus
Primary Observer:
Carl Manthey
Event Date:
2025-06-21
Status:
Unverified
Survey
Site Name:
Great Marsh, Elverson, PA
Province/State:
Pennsylvania
Event Date:
2025-06-21
Time of Day:
Night-Time
Start Time:
20:30
End Time:
22:00
Number of Observers:
4
Primary Observer:
Carl Manthey
Additional Observers:
Bernard Brown, Myrna Villanueva, Diana Cormack
target_species_genus:
unknown
target_species_species:
unknown
Location and Habitat
Location Accuracy (meters):
500-1000
Habitat Type:
Open Freshwater Wetland - Wetland Bog, fen, freshwater marsh
Habitat Type Notes:
Habitat is highly variable. Land was originally a large marsh. It was briefly drained and used as a dairy farm until the 1950s. At that time, it was allowed to revert to a marsh, although a number of ponds were built. The area viewed includes wet marsh with cattails, ponds with spatterdock, swamp with black willow, wet meadows with native perennials, mowed grassy paths, and higher ground with red maple, black cherry, spicebush, and oak. There are also a couple soybean fields and a sheep pasture.
Elevation (meters):
150 - 200
Area Searched (hectares):
7
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): 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:
marginellus
Observation Notes:
very small
Specimen Voucher Number:
Flash Behavior
First Flash Time:
21:00
Last Flash Time:
22:00
First Flash Temp (F):
78
Last Flash Temp (F):
78
Flashes in Pattern:
1
Flash Color:
Yellow
Flash Pattern Period:
longer than scintillans
Flash Duration:
longer than scintillans
Flash Interval:
longer than scintillans
Male Height Zone:
Moderate (3-8 ft)
Flash Location:
5 to 6 feet off the ground in the trees and the top of the shrubs.
Male Flash Behavior:
longer upward flash then a long pause. It was difficult to see the flash pattern as I would lose them after the upward flash.
a smaller firefly
