Choristoneura fumiferana
In 3 days ~10% in a week ~20%
Choristoneura fumiferana, the eastern spruce budworm, is a species of moth of the family Tortricidae native to the eastern United States and Canada. The caterpillars feed on the needles of spruce and fir trees. Eastern spruce budworm populations can experience significant oscillations, with large outbreaks sometimes resulting in wide scale tree mortality. The first recorded outbreaks of the spruce budworm in the United States occurred in about 1807, and since 1909 there have been waves of budworm outbreaks throughout the eastern United States and Canada. In Canada, the major outbreaks occurred in periods circa 1910–20, c. 1940–50, and c. 1970–80, each of which impacted millions of hectares of forest. Longer-term tree-ring studies suggest that spruce budworm outbreaks have been recurring approximately every three decades since the 16th century, and paleoecological studies suggest the spruce budworm has been breaking out in eastern North America for thousands of years.
Budworm outbreaks can have significant economic impacts on the forestry industry. As a result, the eastern spruce budworm is considered one of the most destructive forest pests in North America, and various methods of control are utilized. However, the species is also ecologically important, and several bird species are specialised on feeding on budworms during the breeding season. Several theories exist to explain the cyclical budworm outbreaks. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Gros Morne National Park | 🇨🇦 Canada | |
| 2 | Isle Royale National Park | 🇺🇸 United States | |
| 3 | Banff National Park | 🇨🇦 Canada |
Rare
Under 5% of wildlife watchers report a Spruce Budworm Moth sighting in Chicago on a given day, based on 11 verified sightings from GBIF citizen-science data. It is the 602nd most-seen of the 978 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.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Spruce Budworm Moth in Chicago on a given day, so our monthly data shows no clear season.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Spruce Budworm Moth sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 4 cities where we can rate Spruce Budworm Moth sightings, Chicago ranks 4th at under 5%, level with the leaders once rounded. The best odds are in Montreal (Canada, under 5%), Edmonton (Canada, under 5%) and Toronto (Canada, under 5%).
GBIF citizen-science records
It is estimated from how often the Spruce Budworm Moth is recorded against all the insects logged in Chicago (11 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.
