Observation: Pyractomena sinuata
Primary Observer:
Richard Joyce
Event Date:
2026-06-09
Status:
Unreviewed
Survey
Site Name:
Dwelly Farm Conservation Area – Back Fields East
Province/State:
Massachusetts
Event Date:
2026-06-09
Time of Day:
Night-Time
Start Time:
20:54
End Time:
21:49
Number of Observers:
16
Primary Observer:
Richard Joyce
Additional Observers:
Emily Merlino and 14 firefly walk attendees from the public
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:
Old dairy pasture that surrounded by forest that is now mowed annually. Cool season grasses, goldenrod, and other forbs.
Elevation (meters):
308
Area Searched (hectares):
0.3
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:
With Flash Data
Number Observed:
50+
genus:
pyractomena
Species:
sinuata
Observation Notes:
Captured males were ~9.5 mm.
mGDD (Orange Municipal AP, missing 8 June) was 676
mGDD (Fitchburg Municipal AP) was 759
Specimen Voucher Number:
Flash Behavior
First Flash Time:
21:05
Last Flash Time:
21:49
First Flash Temp (F):
70
Last Flash Temp (F):
67
Flashes in Pattern:
1
Flash Color:
Green
Flash Pattern Period:
not recorded
Flash Duration:
1.5
Flash Interval:
not recorded
Male Height Zone:
Low (0-3 ft), Moderate (3-8 ft)
Flash Location:
Most flashes were at knee to waist height (less than 2 meters) above the tips of the grass and herbs. Displays occurred throughout most of Back Field East, but appeared more dense in the more northern section.
Male Flash Behavior:
Males would emit a greenish glow for over a second while drifting both horizontally and vertically in flight. Some of these glows appeared orange to multiple observers, but were lime green in photographs. Flash pattern period was difficult to record because of the high density of displaying males, but was likely >3 seconds.
A few males were also observed glowing continuously from the vegetation.
Female Flash Behavior:
Not observed.
