Oak Leaf Gall Midge

Oak Leaf Gall Midge

Polystepha pilulae

Daily sighting probability <5% · Rare
at Philadelphia

In 3 days ~10% in a week ~20%

16 Verified sightings at Philadelphia
25 In all 2 parks From 2019 to 2026
September Best month
☀️ Diurnal When it's spotted

About the Oak Leaf Gall Midge

Polystepha pilulae, the oak leaf gall midge, is a species of gall midge in the family Cecidomyiidae. It is found in eastern North America. Wikipedia →

Global Distribution

Parks Where Found

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

Cities Where Found

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

Before you go

What are the chances of seeing an Oak Leaf Gall Midge in Philadelphia?

Rare

Under 5% of wildlife watchers report an Oak Leaf Gall Midge sighting in Philadelphia on a given day, based on 16 verified sightings from GBIF citizen-science data. It is the 327th most-seen of the 632 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.

When is the best time to see an Oak Leaf Gall Midge in Philadelphia?

September

In that month about 10% of wildlife watchers report an Oak Leaf Gall Midge in Philadelphia on a given day, against under 5% in October to August, the lowest months.

What time of day is best to see an Oak Leaf Gall Midge?

Between 9 am and noon

Across all the parks we cover, that three-hour window holds the most Oak Leaf Gall Midge sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.

Is Philadelphia the best place to see an Oak Leaf Gall Midge?

7th of 10

Of the 10 cities where we can rate Oak Leaf Gall Midge sightings, Philadelphia ranks 7th at under 5%. The best odds are in Boston (United States, about 10%), Minneapolis [Saint Paul] (United States, about 10%) and Dallas (United States, about 10%).

Where does the Oak Leaf Gall Midge sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Oak Leaf Gall Midge is recorded against all the insects logged in Philadelphia (16 verified sightings), 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.

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