Compost Fly

Compost Fly

Ptecticus trivittatus

Daily sighting probability ~10% · With luck
at Shenandoah National Park

In 3 days ~10% in a week ~30%

7 Verified sightings at Shenandoah National Park From 2019 to 2026
17 In all 2 parks
August Best month
☀️ Diurnal When it's spotted

About the Compost Fly

Ptecticus trivittatus is a species of soldier fly in the family Stratiomyidae. Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Shenandoah National Park 🇺🇸 United States
~10%
2 Great Smoky Mountains National Park 🇺🇸 United States
<5%

Cities Where Found

# City Country Daily sighting probability
1 Detroit 🇺🇸 United States
~10%
2 Minneapolis [Saint Paul] 🇺🇸 United States
~10%
3 Boston 🇺🇸 United States
~10%
4 Montreal 🇨🇦 Canada
~10%
5 Philadelphia 🇺🇸 United States
~10%
6 Toronto 🇨🇦 Canada
~10%
7 Baltimore 🇺🇸 United States
<5%
8 Washington 🇺🇸 United States
<5%
9 New York City 🇺🇸 United States
<5%
10 Chicago 🇺🇸 United States
<5%

Before you go

What are the chances of seeing a Compost Fly in Shenandoah National Park?

With luck

About 10% of wildlife watchers report a Compost Fly sighting in Shenandoah National Park on a given day, based on 7 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 447th most-seen of the 723 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.

When is the best time to see a Compost Fly in Shenandoah National Park?

June to August

In those months about 10% of wildlife watchers report a Compost Fly in Shenandoah National Park on a given day, against under 5% in September to May, the lowest months.

What time of day is best to see a Compost Fly?

Between 1 and 4 pm

Across all the parks we cover, that three-hour window holds the most Compost Fly sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.

Is Shenandoah National Park the best place to see a Compost Fly?

Yes

Of the 2 parks where we can rate Compost Fly sightings, Shenandoah National Park has the highest daily chance: about 10%. Next come Great Smoky Mountains National Park (United States, under 5%).

Where does the Compost Fly sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Compost Fly is recorded against all the insects logged in Shenandoah National Park (7 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.

← Back to Shenandoah National Park