[All data](/swarmed-data) Field report

# How far the Asian hornet has actually spread across Europe

 Vespa velutina is now recorded in numbers in 13 European countries and is moving north fastest: net of recording effort, spring activity rose 50% across Europe from 2025 to 2026, and 141% in the Netherlands. A hornet reported in spring is the clearest early warning a beekeeper has. Where a 5 km square had no hornet activity the year before, 49.5% of squares with a spring report went on to record late-season activity, against 9.9% without one.

 Built from 451,921 georeferenced records retrieved from GBIF on 2026-08-27, and an Observation.org extract running through 2026-09-06.

## The spread, country by country

 Recorded in numbers by 2025

 Shaded by the year the species was first recorded in numbers, meaning the first year a country logged five or more records. Colour shows arrival year only.

 2004 2025

 Records retrieved 2026-08-27. The timeline runs to 2025, the last complete season.

 First year with 5+ records

- 2004 to 2009
- 2010 to 2014
- 2015 to 2019
- 2020 to 2022
- 2023 onward
- Records, never 5 in a year

 Arrival sequence

- France 2005
- Spain 2012
- Portugal 2012
- Germany 2014
- Belgium 2016
- Netherlands 2017
- Switzerland 2020
- Luxembourg 2020
- Italy 2020
- Sweden 2021
- United Kingdom 2023
- Austria 2024
- Ireland 2025

 Reached Ireland in 2025.

 Dashed: Czechia, Hungary, Denmark. First records, fewer than five in any year.

## Spring reports as an early warning

 49.5%

 of squares where a hornet was reported in spring also recorded late-season activity

 9.9%

 of squares where no hornet was reported in spring recorded late-season activity, at the same recording effort

 In spring there are no colonies yet, only founding queens looking for a nest site. A hornet seen then, in a square with no history, means a nest is likely nearby by August.

 Measured on 10,146 square-years with no late-season record the year before, 1,147 of them carrying a spring report. Adjusted odds ratio 11.93 (95% confidence interval 6.15 to 23.13).

### Where the signal adds least

 Where a square already had late-season hornets the year before, that history does most of the work: 66.9% go on to record activity with no spring report and 83.5% with one, an adjusted odds ratio of 3.77. A spring report matters most on the leading edge, where there is nothing else to go on.

## Moving north fastest

 The further north, the faster the rise. Effort adjusted, spring activity rose 16% in Belgium, 141% in the Netherlands and 249% in Germany, where spring records went from 92 to 577.

 Country | Effort adjusted | Raw spring hornet records | Recording effort

 Belgium | +16% | +68% | +45%

 Netherlands | +141% | +273% | +54%

 Germany | +249% | +527% | +80%

 Change in spring records (1 February to 31 May), 2025 to 2026. Recording effort is the native European hornet, Vespa crabro, counted in the same records.

## Where it has reached, and when

 Vespa velutina, the yellow-legged or Asian hornet, arrived in south-west France around 2004 and has moved outward every year since. It hunts honey bees at the hive entrance, and for a beekeeper on the advancing edge it is the difference between a normal season and losing colonies.

 Country | Recorded in numbers

 France | 2005

 Spain | 2012

 Portugal | 2012

 Germany | 2014

 Belgium | 2016

 Netherlands | 2017

 Switzerland | 2020

 Luxembourg | 2020

 Italy | 2020

 Sweden | 2021

 United Kingdom | 2023

 Austria | 2024

 Ireland | 2025

 First records on the open front, fewer than five in any year: Czechia, Hungary, Denmark.

## How the result holds up

 Every figure above is set against the native European hornet, Vespa crabro: same genus, equally visible, reported by the same people through the same platform, and untouched by the invasion. Its records measure how hard people were looking. A square enters the sample only in a year somebody recorded a native hornet there, so an empty square is one where somebody looked and found nothing.

 Spring Asian hornet records rose 131% from 2025 to 2026 while native hornet records rose 54%, which leaves the 50% rise. Leaving out the single account that supplies about two fifths of the records gives 48%.

 The spring signal holds at every level of recording effort:

 Native hornets recorded | Hornet reported in spring | None reported | Gap

 0 | 38.2% | 5.0% | +33.2 pp

 1 | 55.5% | 8.1% | +47.4 pp

 2 to 3 | 70.9% | 15.1% | +55.8 pp

 4 or more | 86.1% | 31.4% | +54.7 pp

 It also holds across observers. In 89.2% of squares where a spring report was followed by late-season activity, somebody else reported the later hornets. Counting only those, the adjusted odds ratio is 8.55 (4.38 to 16.68).

## Method and source

 The map and arrival years come from GBIF occurrence records for Vespa velutina Lepeletier, 1836 (taxonKey 1311477) carrying coordinates, retrieved on 2026-08-27 and committed as a fixed snapshot. A country is shown as recorded in numbers from the first year it logged five or more records, through 2025.

 The spring sections use a separate Observation.org extract of 280,093 Vespa velutina and 61,280 Vespa crabro records, running through 2026-09-06, compared over 2025 and 2026. Squares are 5 km cells on the European equal-area grid, the spring window is 1 February to 31 May and the late window 1 August to 6 September, capped at the same day in both years. Standard errors are clustered on 200 km blocks. Most records come from Belgium and the Netherlands. Countries that destroy nests on report are excluded (GB, GG, IE, IM, JE), since there a sighting leads to removal.

 British sightings are confirmed by the National Bee Unit through its own reporting route; British beekeepers should report through Asian Hornet Watch.

 The underlying observations belong to the national platforms and naturalists who collected them.

 [Vespa velutina on GBIF](https://www.gbif.org/species/1311477), and the spring-signal records from [Observation.org](https://observation.org/)
