Acossus populi
In 3 days ~20% in a week ~40%
Acossus populi, the aspen carpenterworm, is a moth of the family Cossidae. It is found in the United States in Nevada, Colorado, California and in the northern Rocky Mountains. In Canada it is found in Ontario and British Columbia.
The wingspan is 50–68 mm. The larvae feed on Populus species, mainly Populus tremuloides. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Jasper National Park | 🇨🇦 Canada |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report an Aspen Carpenterworm sighting in Jasper National Park on a given day, based on 7 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 72nd most-seen of the 88 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.
July
In that month about 10% of wildlife watchers report an Aspen Carpenterworm in Jasper National Park on a given day, against under 5% in August to June, the lowest months. That is one of Jasper National Park's wettest months, with about 130 mm of rain against 55 mm in April.
Between 9 pm and midnight
Across all the parks we cover, that three-hour window holds the most Aspen Carpenterworm sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Only Jasper National Park, in our data
Jasper National Park is the only park on Wallace's Line with enough records to rate Aspen Carpenterworm sightings: about 10% of wildlife watchers there report one on a given day.
Same order: Lepidoptera
The closest relatives of the Aspen Carpenterworm that you can see in Jasper National Park (order Lepidoptera, Butterflies and Moths) are Pearl Crescent (about 30%), Red-Spotted Admiral (about 20%) and Mourning Cloak (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Aspen Carpenterworm is recorded against all the insects logged in Jasper National Park (7 verified sightings from 2019 to 2026), 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.
