Phytomyza ilicis
In 3 days ~20% in a week ~40%
Phytomyza ilicis, the holly leaf miner, is a leaf mining fly in the family Agromyzidae, whose larvae burrow into leaves of the holly tree (Ilex aquifolium) leaving characteristic pale trails or leaf mines. Adults of P. ilicis are small with a wing length measuring 2.5–3 millimetres (0.098–0.118 in). They have red eyes and 6–8 pairs of acrostichal bristles on the thorax.
Larvae are pale, leg-less maggots lacking a head capsule and thoracic and abdominal legs like most fly larvae. The dark-brown coloured puparium is formed from the hardened last larval skin. The holly leaf miner is found throughout the holarctic on its host Ilex aquifolium. It is common and widespread in Europe and has been introduced into western Canada and north west USA. Its distribution is probably dependent upon average temperatures; Peterkin and Lloyd found it absent from areas where the mean temperatures of the coldest months of the year falls below −0.5 °C (31.1 °F).
Female Agromyzidae insert an egg in the leaf tissue using an ovipositor. In the case of P. ilicis this poses a problem, because the leaf of the hostplant is unusually tough. Only during the annual... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Wadden Sea National Park | 🇩🇪 Germany | |
| 3 | Great Bear Rainforest | 🇨🇦 Canada |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Liverpool | 🇬🇧 United Kingdom | |
| 2 | Birmingham | 🇬🇧 United Kingdom | |
| 3 | London | 🇬🇧 United Kingdom | |
| 4 | Manchester | 🇬🇧 United Kingdom | |
| 5 | Vancouver | 🇨🇦 Canada | |
| 6 | Berlin | 🇩🇪 Germany | |
| 7 | Brussels | 🇧🇪 Belgium | |
| 8 | Leeds | 🇬🇧 United Kingdom | |
| 9 | Dublin | 🇮🇪 Ireland | |
| 10 | Rotterdam [The Hague] | 🇳🇱 Netherlands |
With luck
About 10% of wildlife watchers report a European Holly Leafminer sighting in Brussels on a given day, based on 17 verified sightings from GBIF citizen-science data. It is the 109th most-seen of the 337 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
January–August and November
In those months about 10% of wildlife watchers report a European Holly Leafminer in Brussels on a given day, against under 5% in September–October and December, the lowest months.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most European Holly Leafminer sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
7th of 17
Of the 17 cities where we can rate European Holly Leafminer sightings, Brussels ranks 7th at about 10%. The best odds are in Liverpool (United Kingdom, about 40%), Birmingham (United Kingdom, about 20%) and London (United Kingdom, about 20%).
Same order: Diptera
The closest relatives of the European Holly Leafminer that you can see in Brussels (order Diptera, Flies) are Marmalade Hover Fly (about 20%), Common Drone Fly (about 20%) and Yellow-Haired Sun Fly (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the European Holly Leafminer is recorded against all the insects logged in Brussels (17 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.
