Xanthogaleruca luteola
In 3 days ~40% in a week ~70%
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 Rome on a given day, based on 74 verified sightings from GBIF citizen-science data. It is the 11th most-seen of the 289 insects we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
June and July
In those months about 30% of wildlife watchers report an Elm Leaf Beetle in Rome on a given day, against under 5% in November to February, the lowest months. Those are among Rome's driest months, with about 30 mm of rain a month against 110 mm in November.
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.
Among the best
Of the 32 cities where we can rate Elm Leaf Beetle sightings, Rome ranks 4th at about 20%, level with the leaders once rounded. The best odds are in Madrid (Spain, about 20%), 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 Rome (family Chrysomelidae, Leaf Beetles) are Timarcha nicaeensis (about 10%), Bronze Beetle (about 10%) and Lachnaia italica (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 Rome (74 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.
