Western Grape Rootworm

Western Grape Rootworm

Bromius obscurus

Daily sighting probability <5% · Rare
at Saint Petersburg

In 3 days ~10% in a week ~30%

30 Verified sightings at Saint Petersburg
17 In 1 park From 2019 to 2026
June Best month
☀️ Diurnal When it's spotted

About the Western Grape Rootworm

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 →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Glacier National Park 🇺🇸 United States
~10%

More parks will be added in future updates.

Cities Where Found

# City Country Daily sighting probability
1 Helsinki 🇫🇮 Finland
~10%
2 Stockholm 🇸🇪 Sweden
<5%
3 Saint Petersburg 🇷🇺 Russia
<5%
4 Moscow 🇷🇺 Russia
<5%

Before you go

What are the chances of seeing a Western Grape Rootworm in Saint Petersburg?

Rare

Under 5% of wildlife watchers report a Western Grape Rootworm sighting in Saint Petersburg on a given day, based on 30 verified sightings from GBIF citizen-science data. It is the 83rd most-seen of the 448 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.

When is the best time to see a Western Grape Rootworm in Saint Petersburg?

May to July

In those months about 10% of wildlife watchers report a Western Grape Rootworm in Saint Petersburg on a given day, against under 5% in August to April, the lowest months.

What time of day is best to see a Western Grape Rootworm?

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.

Is Saint Petersburg the best place to see a Western Grape Rootworm?

3rd of 4

Of the 4 cities where we can rate Western Grape Rootworm sightings, Saint Petersburg ranks 3rd at under 5%. The best odds are in Helsinki (Finland, about 10%) and Stockholm (Sweden, under 5%).

Where does the Western Grape Rootworm sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Western Grape Rootworm is recorded against all the insects logged in Saint Petersburg (30 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.

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