Goldenrod Gall Fly

Goldenrod Gall Fly

Eurosta solidaginis

Daily sighting probability <5% · Rare
at New York City

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

40 Verified sightings at New York City
43 In all 2 parks From 2019 to 2026
February Best month
☀️ Diurnal When it's spotted

About the Goldenrod Gall Fly

The goldenrod gall fly (Eurosta solidaginis), also known as the goldenrod ball gallmaker, is a species of fly native to North America. The species is best known for the characteristic galls it forms on several species in the Solidago, or goldenrod, genus. The fly's eggs are inserted near the developing buds of the plant. After hatching, the larvae migrate to an area below the plant's developing buds, where they then induce the plant's tissues to form into the hardened, bulbous chamber referred to as a gall. E. solidaginis’s interactions with its host plant(s) and insect, as well as avian, predators have made it the centerpiece of much ecological and evolutionary biology research, and its tolerance of freezing temperatures has inspired studies into the anti-freeze properties of its biochemistry.

Eurosta solidaginis is in the order Diptera and the family Tephritidae. The Tephritidae are commonly referred to as fruit flies, a common name they share with the Drosophilidae family. The goldenrod gall fly was first put into the genus Eurosta by D. W. Cocquillet in 1910. Two subspecies exist: E. solidaginis subsp. solidaginis and E. solidaginis subsp. fascipennis, distinguished... Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Elk Island National Park 🇨🇦 Canada
~10%
2 Great Smoky Mountains National Park 🇺🇸 United States
~10%

Cities Where Found

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

Before you go

What are the chances of seeing a Goldenrod Gall Fly in New York City?

Rare

Under 5% of wildlife watchers report a Goldenrod Gall Fly sighting in New York City on a given day, based on 40 verified sightings from GBIF citizen-science data. It is the 529th most-seen of the 1623 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 a Goldenrod Gall Fly in New York City?

Any time of year

In every month with enough records, under 5% of wildlife watchers report a Goldenrod Gall Fly in New York City on a given day, so our monthly data shows no clear season.

What time of day is best to see a Goldenrod Gall Fly?

Between noon and 3 pm

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

Is New York City the best place to see a Goldenrod Gall Fly?

10th of 10

Of the 10 cities where we can rate Goldenrod Gall Fly sightings, New York City ranks 10th at under 5%. The best odds are in Montreal (Canada, about 10%), Toronto (Canada, about 10%) and Minneapolis [Saint Paul] (United States, about 10%).

Where does the Goldenrod Gall Fly sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Goldenrod Gall Fly is recorded against all the insects logged in New York City (40 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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