Eurosta solidaginis
In 3 days ~20% in a week ~40%
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 →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Elk Island National Park | 🇨🇦 Canada | |
| 2 | Great Smoky Mountains National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Montreal | 🇨🇦 Canada | |
| 2 | Toronto | 🇨🇦 Canada | |
| 3 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 4 | Calgary | 🇨🇦 Canada | |
| 5 | Chicago | 🇺🇸 United States | |
| 6 | Houston | 🇺🇸 United States | |
| 7 | Washington | 🇺🇸 United States | |
| 8 | Edmonton | 🇨🇦 Canada | |
| 9 | Boston | 🇺🇸 United States | |
| 10 | New York City | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Goldenrod Gall Fly sighting in Toronto on a given day, based on 374 verified sightings from GBIF citizen-science data. It is the 87th most-seen of the 1689 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
March–April and June–January
In those months about 10% of wildlife watchers report a Goldenrod Gall Fly in Toronto on a given day, against under 5% in February and May, the lowest months.
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.
Among the best
Of the 10 cities where we can rate Goldenrod Gall Fly sightings, Toronto ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Montreal (Canada, about 10%).
GBIF citizen-science records
It is estimated from how often the Goldenrod Gall Fly is recorded against all the insects logged in Toronto (374 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.
