Oulema melanopus
In 3 days ~10% in a week ~20%
The cereal leaf beetle (Oulema melanopus) is a significant crop pest, described by Carl Linnaeus in 1758. One generation of this beetle is produced a year. Adults feed before winter and spend most of their overwintering time in protected areas such as wind rows, crop stubble, and tree bark crevices. Adults mate once the temperature warms to above 9–10 degrees Celsius (or 44.6 degrees F) and females have a relatively long laying period (about 45–60 days), when they deposit eggs on the undersides of leaves. The larvae hatch in 7–15 days, and start the most damaging eating of the entire lifecycle. These larvae mature in 12–20 days. Larvae are the greatest threat to crops, as they eat the superficial layer of leaves, hindering the leaves' photosynthetic potential. According to Kon, Zabik, Webster, and Leavitt, a chemical factor attracts the beetles to leaves, and that chemical factor is directly related to hydrophobicity. Pupation occurs in soil, with the adults emerging in 20–25 days, ready to start the cycle again.
Eggs are cylindrical and round, about 0.9 mm long and 0.4 mm wide. Eggs are often laid along the midvein on the undersides of leaves. They are bright yellow... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
Rare
Under 5% of wildlife watchers report a Cereal Leaf Beetle sighting in Paris on a given day, based on 5 verified sightings from GBIF citizen-science data. It is the 827th most-seen of the 916 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 Cereal Leaf Beetle in Paris on a given day, so our monthly data shows no clear season.
Yes
Of the 2 cities where we can rate Cereal Leaf Beetle sightings, Paris has the highest daily chance: under 5%. Next come Toronto (Canada, under 5%).
Same family: Chrysomelidae
The closest relatives of the Cereal Leaf Beetle that you can see in Paris (family Chrysomelidae, Leaf Beetles) are Rosemary Beetle (about 10%), Elm Leaf Beetle (about 10%) and Alder Leaf Beetle (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Cereal Leaf Beetle is recorded against all the insects logged in Paris (5 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.
