Observation: Pyractomena borealis

Observation: Pyractomena borealis

Primary Observer:

Carol Croy

Event Date:

2025-04-16

Status:

Verified

Survey

Site Name:

Falls Ridge

Province/State:

Virginia

Event Date:

2025-04-16

Time of Day:

Night-Time

Start Time:

21:00

End Time:

23:00

Number of Observers:

2

Primary Observer:

Carol Croy

Additional Observers:

Steve Croy

Target Species Genus:

unknown

Target Species Species:

unknown

Location and Habitat

Location Accuracy (meters):

0-25

Habitat Type:

Woodland/Forest - Trees dominant, and in the over-story

Habitat Type Notes:

Mixed oak, hickory, poplar, maple, buckeye, some pine, previously ash

Elevation (meters):

549

Area Searched (hectares):

1

Artificial Light Sources

Vehicles: No
Street Lights: No
Buildings: Yes

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

Artificial Light Notes:

Generally dark, site is on a ridgetop accessed by a private gravel road and only 1 house present. Adjacent to Falls Ridge Nature Conservancy Preserve. In a valley sparsely populated due to private land ownership in large parcels.

Observation

Observation Type:

Flashing

Number Observed:

11-50

Genus:

Pyractomena

Species:

borealis

Observation Notes:

Other possible species ruled out due to time of year and flashing behavior. This population has been observed here for a number of years. Finally figured out what possible species this might be and have joined the firefly atlas.

Specimen Voucher Number:

Flash Behavior

First Flash Time:

21:00

Last Flash Time:

23:00

First Flash Temp (F):

70

Last Flash Temp (F):

68

Flashes in Pattern:

1

Flash Color:

Yellow

Flash Pattern Period:

1

Flash Duration:

1

Flash Interval:

3

Male Height Zone:

High (over 8 ft)

Flash Location:

In woodland and a small opening within the woodland dominated by shrubs and scattered small trees

Male Flash Behavior:

Single warm flashes every couple of seconds. Later in the evening observed random single flashes.

Female Flash Behavior:

 

1 thought on “Observation: Pyractomena borealis”

  1. Thank you for submitting this firefly observation! I agree that this is Pyractomena borealis because no other species are flashing this time of year, and the single flashes high in the trees aligns well with this species.

    One note about the flash pattern terminology–

    You can refer to the diagrams on the back of the Firefly Atlas data-sheet for a visual reminder of what each term means.

    For Pyractomena borealis, I would expect flash pattern details that looked something like this:

    Flash pattern period: 3-4 seconds
    Flash duration: 0.25 seconds, “quick” or “brief”
    Flash interval: 2.75 seconds (flash pattern period minus flash duration)

    I know these terms can be confusing, but they are necessary because of fireflies with more complex flash patterns (for example ones with long glows or multi-pulse flash patterns).

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