Neogalerucella calmariensis
In 3 days ~10% in a week ~20%
Galerucella calmariensis, sometimes Neogalerucella calmariensis, is a species of leaf beetle in the family Chrysomelidae. It is commonly known as the black-margined loosestrife beetle and is native to Europe and Northern Asia (excluding China) where both adults and larvae feed on purple loosestrife (Lythrum salicaria). It has been introduced in North America as a biological control agent for purple loosestrife.
The black-margined loosestrife beetle is cylindrical in shape, mid brown, three to six millimetres long and half that width. When seen from above it often has two blackish lateral lines down either side. The eggs are spherical, white and usually topped with frass. The larvae are yellow speckled with black and resemble small caterpillars.
Adults overwinter in leaf litter near purple loosestrife plants. They emerge in the spring and start to feed on the young growth. They cause damage to the leaves characterised by neat rounded shot holes between the veins. The females lay up to 500 eggs from May to July in small batches on leaves and stems. On hatching, the first instar larvae feed on growing shoot tips and may kill them. Later instars feed on... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Tokyo | 🇯🇵 Japan | |
| 2 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 3 | Boston | 🇺🇸 United States | |
| 4 | Toronto | 🇨🇦 Canada | |
| 5 | London | 🇬🇧 United Kingdom |
Rare
Under 5% of wildlife watchers report a Black-Margined Loosestrife Beetle sighting in London on a given day, based on 8 verified sightings from GBIF citizen-science data. It is the 1153rd most-seen of the 1504 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 Black-Margined Loosestrife Beetle in London on a given day, so our monthly data shows no clear season.
Among the best
Of the 5 cities where we can rate Black-Margined Loosestrife Beetle sightings, London ranks 5th at under 5%, level with the leaders once rounded. The best odds are in Tokyo (Japan, under 5%), Minneapolis [Saint Paul] (United States, under 5%) and Boston (United States, under 5%).
Same family: Chrysomelidae
The closest relatives of the Black-Margined Loosestrife Beetle that you can see in London (family Chrysomelidae, Leaf Beetles) are Rosemary Beetle (about 20%), Alder Leaf Beetle (about 10%) and Hawthorn Leaf Beetle (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Black-Margined Loosestrife Beetle is recorded against all the insects logged in London (8 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.
