Xanthogaleruca luteola
In 3 days ~50% in a week ~80%
Xanthogaleruca luteola, commonly known as the elm-leaf beetle, is a beetle species in the family Chrysomelidae that is native to Europe but invasive in other parts of the world. The imago (adult beetle) is 6–8 mm in length, and ranges from yellow to green in colour, with a spot on its head, an hourglass mark and two spots on the pronotum, and a broad, dark stripe along the edge of each elytron. The larvae are usually black, occasionally black and yellow, with multiple rows of dots on the back and on the sides and < 13 mm long. The pupae are orange-yellow with black chaetae. The eggs are yellow, and laid in spindle-like clusters of < 25 on the undersides of the elm leaves.
These beetles are common in the Western Palearctic realm from Portugal to Central Asia. Indigenous to Europe, they were accidentally introduced to North America and Australia, and are now widespread, and are serious pests in Australia and parts of North America.
X. luteola is a serious pest of the elm. Both the adults and larvae feed on the emergent leaves of the elm. Repeated heavy infestation rarely kills the tree outright, but weakens it, rendering... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Camargue | 🇫🇷 France | |
| 2 | Sierra Nevada National Park | 🇪🇸 Spain | |
| 3 | Cévennes National Park | 🇫🇷 France | |
| 4 | Pyrénées National Park | 🇫🇷 France |
Possible
About 20% of wildlife watchers report an Elm Leaf Beetle sighting in Madrid on a given day, based on 277 verified sightings from GBIF citizen-science data. It is the 6th most-seen of the 457 insects we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
August
In that month about 40% of wildlife watchers report an Elm Leaf Beetle in Madrid on a given day, against about 10% in January–May and October–November, the lowest months. That is one of Madrid's driest months, with about 15 mm of rain against 65 mm in October.
Between 9 pm and midnight
Across all the parks we cover, that three-hour window holds the most Elm Leaf Beetle sightings with a recorded time, and about half of them come between 6 pm and 6 am: it is seen both by day and at night.
Yes
Of the 32 cities where we can rate Elm Leaf Beetle sightings, Madrid has the highest daily chance: about 20%. Next come Mendoza (Argentina, about 20%) and Barcelona (Spain, about 20%).
Same family: Chrysomelidae
The closest relatives of the Elm Leaf Beetle that you can see in Madrid (family Chrysomelidae, Leaf Beetles) are Bronze Beetle (about 20%), Rosemary Beetle (about 10%) and Cryptocephalus rugicollis (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Elm Leaf Beetle is recorded against all the insects logged in Madrid (277 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.
