Cassida rubiginosa
In 3 days ~10% in a week ~20%
The thistle tortoise beetle (Cassida rubiginosa) is a species of beetle in the subfamily Cassidinae (tortoise beetles) and the genus Cassida. The thistle tortoise beetle can be recognized by its green, rounded back and it can be found on thistle plants in many regions of North America and Europe. The thistle tortoise beetle was first discovered in 1902 in Lévis, Quebec. In 1931, Nellie F. Paterson was the first to document the mature larva. Later, the instar larva of this species was first recorded in 2004 by Jolanta Świętojańska. The thistle tortoise beetle exhibits multiple defense behaviors, such as a flexible shield, providing a barrier against the mandibles of predators, and an excretion that protects the eggs as well.
Its ability to massively consume and damage thistle plants has also made this beetle a well known biological control agent in many countries, including the United States, Canada, and Switzerland. However, in some cases, the impact of these beetles has been limited due to parasitism preventing their accumulation in regions of thistle targeted for biological control.
The thistle tortioise beetles measure 6.0–8.0 mm in length. Like all Cassida, its... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Elk Island National Park | 🇨🇦 Canada | |
| 2 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 3 | Shenandoah National Park | 🇺🇸 United States | |
| 4 | Wadden Sea National Park | 🇩🇪 Germany | |
| 5 | Pyrénées National Park | 🇫🇷 France |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Birmingham | 🇬🇧 United Kingdom | |
| 2 | Rotterdam [The Hague] | 🇳🇱 Netherlands | |
| 3 | Manchester | 🇬🇧 United Kingdom | |
| 4 | Bucharest | 🇷🇴 Romania | |
| 5 | London | 🇬🇧 United Kingdom | |
| 6 | Helsinki | 🇫🇮 Finland | |
| 7 | Liverpool | 🇬🇧 United Kingdom | |
| 8 | Kyiv | 🇺🇦 Ukraine | |
| 9 | Edmonton | 🇨🇦 Canada | |
| 10 | Toronto | 🇨🇦 Canada |
Rare
Under 5% of wildlife watchers report a Thistle Tortoise Beetle sighting in Minneapolis [Saint Paul] on a given day, based on 9 verified sightings from GBIF citizen-science data. It is the 458th most-seen of the 672 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 Thistle Tortoise Beetle in Minneapolis [Saint Paul] 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 Thistle Tortoise Beetle sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
15th of 20
Of the 20 cities where we can rate Thistle Tortoise Beetle sightings, Minneapolis [Saint Paul] ranks 15th at under 5%. The best odds are in Birmingham (United Kingdom, about 10%), Rotterdam [The Hague] (Netherlands, about 10%) and Manchester (United Kingdom, about 10%).
Same family: Chrysomelidae
The closest relatives of the Thistle Tortoise Beetle that you can see in Minneapolis [Saint Paul] (family Chrysomelidae, Leaf Beetles) are Swamp Milkweed Leaf Beetle (about 10%), Spotted Cucumber Beetle (about 10%) and Lily Leaf Beetle (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Thistle Tortoise Beetle is recorded against all the insects logged in Minneapolis [Saint Paul] (9 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.
