Bromius obscurus
In 3 days ~20% in a week ~50%
Bromius obscurus, the western grape rootworm, is a species of beetle in the leaf beetle family. It is the only member of the genus Bromius. The distribution of the species is holarctic; it can be found in North America, wide parts of Europe, and Asia. The species is a known pest of grape vines in Europe and western North America.
The genus is named after Bromius, an epithet of the Greek god Dionysus. Bromius obscurus was first described as Chrysomela obscura by Carl Linnaeus in his 1758 10th edition of Systema Naturae. In 1836, the genus Bromius was first established by Louis Alexandre Auguste Chevrolat in Dejean's Catalogue des Coléoptères, including Linnaeus's Chrysomela obscura as well as the species Eumolpus hirtus (now in Trichochrysea) and Cryptocephalus vitis (now a synonym of Bromius obscurus). In 1837, William Kirby established the name Adoxus (derived from the Greek for "inglorious") as a subgenus of Eumolpus, with the species Cryptocephalus vitis as the type. Adoxus was later found to be a synonym of Bromius, though historically some entomologists preferred to use the name Adoxus, since at the time it was thought Chevrolat's name was... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Glacier National Park | 🇺🇸 United States |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Helsinki | 🇫🇮 Finland | |
| 2 | Stockholm | 🇸🇪 Sweden | |
| 3 | Saint Petersburg | 🇷🇺 Russia | |
| 4 | Moscow | 🇷🇺 Russia |
With luck
About 10% of wildlife watchers report a Western Grape Rootworm sighting in Glacier National Park on a given day, based on 17 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 55th most-seen of the 147 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 50%, if each day is a fresh chance.
June to September
In those months about 10% of wildlife watchers report a Western Grape Rootworm in Glacier National Park on a given day, against under 5% in October to May, the lowest months.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Western Grape Rootworm sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Only Glacier National Park, in our data
Glacier National Park is the only park on Wallace's Line with enough records to rate Western Grape Rootworm sightings: about 10% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Western Grape Rootworm is recorded against all the insects logged in Glacier National Park (17 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.
