Otiorhynchus sulcatus
In 3 days ~20% in a week ~30%
The black vine weevil (Otiorhynchus sulcatus) is an insect native to Europe but common in North America as well. It is a pest of many garden plants. The adult weevil is matte black with fused wing covers, and is unable to fly. It feeds at night on the outer edges of leaves, causing the leaves to have a notched margin. Broadleaved evergreen plants such as Camellia, Rhododendron, Euonymus and Bergenia are particularly prone to damage, although a wide range of different garden plants are susceptible to attack.
Female weevils have the ability to reproduce parthenogenetically with fertilisation of eggs required to produce males, though no males have been observed. This form of parthenogenesis is known as thelytoky. Grubs grow up to 1 cm in length, have a slightly curved, legless body and are creamy white in colour with a tan-brown head. They live below the soil surface, and feed on roots and cambium at the base of trunks. They mostly cause damage to herbaceous plants, particularly those growing in containers, where root growth is restricted. Severe infestations can result in complete root destruction and hence plant death.
Their host plant genera include... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Egmont National Park | 🇳🇿 New Zealand | |
| 2 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 3 | Great Bear Rainforest | 🇨🇦 Canada | |
| 4 | Acadia National Park | 🇺🇸 United States | |
| 5 | Wadden Sea National Park | 🇩🇪 Germany | |
| 6 | Bavarian Forest National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Manchester | 🇬🇧 United Kingdom | |
| 2 | Liverpool | 🇬🇧 United Kingdom | |
| 3 | Copenhagen | 🇩🇰 Denmark | |
| 4 | Birmingham | 🇬🇧 United Kingdom | |
| 5 | Rotterdam [The Hague] | 🇳🇱 Netherlands | |
| 6 | Amsterdam | 🇳🇱 Netherlands | |
| 7 | Portland | 🇺🇸 United States | |
| 8 | Helsinki | 🇫🇮 Finland | |
| 9 | Warsaw | 🇵🇱 Poland | |
| 10 | London | 🇬🇧 United Kingdom |
With luck
About 10% of wildlife watchers report a Black Vine Weevil sighting in Chicago on a given day, based on 120 verified sightings from GBIF citizen-science data. It is the 133rd most-seen of the 978 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 30%, if each day is a fresh chance.
July to October
In those months about 10% of wildlife watchers report a Black Vine Weevil in Chicago on a given day, against under 5% in November to June, the lowest months.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Black Vine Weevil sightings with a recorded time, and about half of them come between 6 am and 6 pm: it is seen both by day and at night.
27th of 44
Of the 44 cities where we can rate Black Vine Weevil sightings, Chicago ranks 27th at about 10%. The best odds are in Manchester (United Kingdom, about 20%), Liverpool (United Kingdom, about 10%) and Copenhagen (Denmark, about 10%).
GBIF citizen-science records
It is estimated from how often the Black Vine Weevil is recorded against all the insects logged in Chicago (120 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.
