Adelges cooleyi
In 3 days ~10% in a week ~20%
The gall adelgid (Adelges cooleyi) is an adelgid species that produces galls in spruce trees. They infect the new buds of native spruce trees in the foothills of the Rocky Mountains in the spring. They also attack blue spruce to a lesser degree. The insects complete two generations within the year. They require two different trees for its life cycle, the second being the Rocky Mountain Douglas-fir. They may also attack Sitka, Engelmann, or white spruce. The many different species of adelgids produce different galls on different spruce species.
The Cooley spruce gall adelgid (Adelges cooleyi Gillette) is mainly a western species that usually alternates between white spruce and Douglas fir. It is rare in eastern Canada. In Ontario, the galls are found mostly on Colorado spruce.
The infection is most noticeable on spruce in the spring, May to June, when the galls appear. This infection may be mistakenly diagnosed to be caused by worms, grubs, or even as a sex organ of the spruce. Spruce pollen, however, is released from a smaller structure that lacks needles. The galls are characterized by this pineapple-like form, with a length of 0.5 cm to 8 cm depending on the... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Jasper National Park | 🇨🇦 Canada | |
| 2 | Banff National Park | 🇨🇦 Canada | |
| 3 | Rocky Mountain National Park | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Douglas Fir Adelgid sighting in Seattle on a given day, based on 7 verified sightings from GBIF citizen-science data. It is the 332nd most-seen of the 428 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 Douglas Fir Adelgid in Seattle on a given day, so our monthly data shows no clear season.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Douglas Fir Adelgid 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 3 cities where we can rate Douglas Fir Adelgid sightings, Seattle ranks 3rd at under 5%, level with the leaders once rounded. The best odds are in Calgary (Canada, under 5%) and Edmonton (Canada, under 5%).
GBIF citizen-science records
It is estimated from how often the Douglas Fir Adelgid is recorded against all the insects logged in Seattle (7 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.
