Chris van Swaay

Distribution- (occupancy-) trend tells a different story than the population trend. The distribution of the Gatekeeper (P tithonus, oranje zandoogje) in NL is stable, where the populationsize has declined with 70% between 1992 and 2010.

The Large Skipper (Ochlodes sylvanus, groot dikkopje) is not only declining in NL but in the whole EU, where we can see a reduction in populationsize with appr 50%. www.butterfly-monitoring.eu #eBMS

The small Eastern Baton Blue (Pseudophilotes vicrama) declined in most of N and C Europe, but is still widespread in SE Europe. It occurs on dry grasslands on sandy or stony soils, south-facing slopes with grassy vegetation, on steep slopes, in rocky gullies, on railway embankments, on road verges

Female Meleager's Blue (Polyommatus daphnis, getand blauwtje) are really beautiful butterflies. In S and SE Europe they are widespread, in C Europe local.

Pity, also as measures which will have to be taken for art 10 (pollinators, measures and monitoring obliged) will also work for the GBI species (as butterflies are part of the four pollinator groups). Also monitoring would have benifited. Would have been effective use of resources.

Trend van sprinkhanen en krekels, 1990-2023 De omvang van het verspreidingsgebied van sprinkhaan- en krekelsoorten is sinds 1990 gemiddeld met 27% toegenomen. Echter, bijna de helft van de soorten vertoont juist een neerwaartse trend in verspre...

www.clo.nl/indicatoren/...

Northern Chequered Skipper (C silvicola, geelbont dikkopje): Vulnerable (A2b) in EU (www.bc-europe.eu/webpage.php?...) because of population declines on European Butterfly Monitoring transects in eBMS (www.butterfly-monitoring.net).

Really nice paper from @tiff-ki.bsky.social & co. shows no overall decline in butterfly species richness in Sulawesi over 166 yrs, but changing communities with endemics & forest specialists declining. Short-term trends unreliable measures of long term. royalsocietypublishing.org/doi/10.1098/... 🌏

A Museum specimen of now extinct Madeiran Large White, Pieris wollastoni (Photo: Sam Ellis)

We are also deeply saddened that the Madeiran Large White, Pieris wollastoni, is now officially extinct: it was last seen in 1986. The full report can be downloaded here www.bc-europe.eu/documents/68...

Front cover of the European Butterfly Red List, showing Polyommatus humedasae. The report can be downloaded at https://www.bc-europe.eu/webpage.php?name=red-list-butterflies-2025

The new European Butterfly Red List is published today, with worrying findings. Over 1/4 (28%) of Europe’s 442 species are threatened with extinction or are close to being so. The situation is far worse for our 148 endemic species, 40% are now threatened or nearly so www.bc-europe.eu/webpage.php?...

The new European Butterfly Red List shows that butterflies are under increasing threat across Europe, with the number of species at risk of extinction up from 37 to 65 (73%) in the last 10 years. See our Press Release www.bc-europe.eu/documents/68...

Ecoloog over het teveel aan stikstof: ‘De zieke heide kan worden hersteld, maar elk medicijn heeft bijwerkingen’

Ecoloog over het teveel aan stikstof: ‘De zieke heide kan worden hersteld, maar elk medicijn heeft bijwerkingen’

Crazy but well worth 4 minutes of your day.

Now the 2025 field season for butterflies has come to an end, it is a good moment to look back at the great work of the recorders of Dutch Butterfly Monitoring transects. Almost 400,000 butterflies counted in 2025 on 1372 locations, 8,5 million since 1990 on 212,327 km. Thanks for all hard work!

2025 will mark another bad year for the Dark Green Frit (grote parelmoer, S aglaja) with numbers comparable to 2023 and 2024 in NL (=low). Once widespread throughout the country, and numbers ten years ago still good, now reasonable numbers only on Vlieland and N-Texel (the islands in the NW).

2025 marks a very bad year for the Glanville Frit (veldparelmoer, M cinxia) in NL. Only the coastal population had >10 butterflies, on the inland ones the species almost vanished. Poor weather in 2024 made few larvae enter last winter.

The Painted Lady (distelvlinder, V cardui) was only seen in low numbers on Dutch Butterfly Monitoring transects this year. It is a migrant species, and the graphs show that 1996, 2003, 2009 and 2019 had large invasions, the other years just a few managed their way to NL.

Veel meer natuur nodig om nuttige insecten voor de landbouw te behouden Regels van de EU die tot herstel van de insectenpopulatie moeten leiden zijn ontoereikend, blijkt uit Wagenings onderzoek dat donderdag gepubliceerd is in het wetenschappelijke tijdschrift Science.

Veel meer natuur nodig om nuttige insecten voor de landbouw te behouden

Veel meer natuur nodig om nuttige insecten voor de landbouw te behouden Regels van de EU die tot herstel van de insectenpopulatie moeten leiden zijn ontoereikend, blijkt uit Wagenings onderzoek dat donderdag gepubliceerd is in het wetenschappelijke tijdschrift Science.

www.trouw.nl/duurzaamheid...

The Swallowtail (koninginnenpage, P machaon) had a good year on Dutch Butterfly Monitoring transects, clearly better than 2024 (though we have had better years). Exceptional was the large 3rd generation, which is usually small in NL.

The addition of flexcounts, as eg 15min counts, to Dutch Butterfly Monitoring transects, makes it possible to produce detailed flight curves. Although 2025 was warmer, the White Admiral (kleine ijsvogel, L camilla) had an earlier start in 2024. Also watch the small 2nd gen.

An interesting pattern for the abundance of the Common Blue (icarusblauwtje, P icarus) on Dutch Butterfly Monitoring transects: a large and early 1st gen, followed by a smaller 2nd gen (which is normally larger than the 1st gen) and a small 3rd gen right now. Food quality in summer has been poor.

Semi-natural grasslands as a nature-based solution for climate change mitigation: An assessment of carbon and plant communities across age gradients Semi-natural grasslands have the potential to sequester carbon and enhance biodiversity and therefore offer opportunities as nature-based solutions fo…

Semi-natural grasslands as a nature-based solution for climate change mitigation: An assessment of carbon and plant communities across age gradients...

www.sciencedirect.com/science/arti...

Though I wonder, because it is normally typical for C hyale to be attrackted to its host plant, C alfacariensis feeds on H comosa and Coronilla varia and probably others). They can only be seperated by DNA or by larvae (which are relatively easy to id).

It is clearly a Colias hyale/alfacariensis, which cannot be separated in the field, but C hyale does not occur (as far as I know) south of the Alps, so this must be alfacariensis.

The Hummingbird hawk-moth (kolibrievlinder, Macroglossum stellatarum) is a climate opportunist from the south, and they love warm weather. Numbers on Dutch Butterfly Monitoring transects were high this summer, and the next generation just started. So watch out for these 'hummingbirds' in your garden

Colias alfacariensis

This is a Clouded Yellow Colias croceus, another species, and a migrant from the south.

It's been a while since we had a good migration year for the Pale Clouded Yellow (gele luzernevlinder, C hyale) on Dutch Butterfly Monitoring transects, but finally numbers are comparable to 1992, 2003, 2006 and 2017. The species declined in C Europe, the origin of our butterflies.

No, we don’t monitor hibernators, would be interesting.