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

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

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

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.

After a great start this spring the Peacock (dagpauwoog, A io) had a poor 1st gen in July, and the 2nd gen is more or less absent on Dutch Butterfly Monitoring transects. Numbers are now much lower than in 2024.

Yesterday I bumped into this fresh male Sooty Copper (bruine vuurvlinder, L tityrus), of what will probably become a 3rd gen. Also a new site for me on S Veluwe. This species shows a large decline, esp. in the north of NL, since I started butterflying.

Not that long ago in August Buddleia's could be covered with Small Tortoiseshells (A urticae, kleine vos). On eBMS transects and 15min counts (www.butterfly-monitoring.net) this butterfly is now restricted to higher elevations or latitudes. Open squares=counted in that period.

An update of the Pieris-whites on Dutch Butterfly Monitoring transects show they all have a relatively poor 3rd gen this year. The reason recorders feel they 'only count Whites' is because all other species are doing even worse, maybe except for C hyale and C argiades in the SE.

Clouded and Pale Clouded Yellow (C hyale+crocea, gele en oranje luzernevlinder) are migrants in NL and show large year-year fluctuations in density on Dutch Butterfly Monitoring transects. Before 1980 C hyale was considered more abundant, now it is C croceus. Numbers for 2025 up to now.

Up to July numbers of Red Admiral (Vanessa atalanta) were good on Dutch Butterfly Monitoring transects, but since then they plumeted and now mid-August we have a negative record, as never before there were so few of them counted. This is most probably linked to poor nettle quality.

We had a large 1st gen of the Common Blue (P icarus, icarusblauwtje) on Dutch Butterfly Monitoring transects. But where the 2nd gen is usually twice as big, in 2025 it was even smaller, probably because of poor foodplant quality as a result of dry conditions in spring. Will we have a 3rd gen?

As a true climate opportunist the Short-tailed Blue (C argiades, staartblauwtje), which arrived in NL in 2009, profits from hot and dry summers caused by climate change. Numbers on Dutch Butterfly Monitoring transects now higher than ever.

The mean number of butterflies on Dutch Butterfly Monitoring transects is now very low as compared to other years since 1990 (though 2024 was worse). With such low numbers flowers in gardens also stay empty: there are simply no butterflies around to visit them.

The next generation of Southern Small White (P mannii) has started, I just made this photo in the garden. You notice them as they are a bit smaller than Small Whites and have a slightly different way of flying. This generation should have a large and dark square middle spot (as on the photo).

The White-letter hairstreak (S w-album, Iepenpage) was always very rare in NL, but is now widely distributed over N and C NL. This is partly as we now know how to spot the species, but also true expansion.

2025 so far is a good year for the Southern Small White (P mannii, scheefbloemwitje) on Dutch Butterfly Monitoring transects. With the next generation just starting we hope numbers will peak in September.

Britain has gained a new butterfly! The long-anticipated arrival of Southern Small White (Pieris mannii) has been confirmed.

When I started butterflying the Speckled wood (P aegeria, bont zandoogje) was restricted to woodlands in a few regions in NL, now it can be found all over the country. 2025 seems to become a good year on Dutch Butterfly Monitoring transects.

When I started butterflying in the 1980s you could see hundreds or thousands of Graylings (heivlinder, H semele) on dry heathlands in August. It could be extremely abundant. But since then numbers went down and 2025 looks like a new low on Dutch Butterfly Monitoring transects.

The start of the flight period for Large Skipper (O sylvanus) on Dutch Butterfly Monitoring transects is more or less unchanged, but peaks lower and ends earlier. Before 2014 numbers end of July would be around half of the peak numbers, now they are close to 0. Numbers 2025 little better than 2024.

Found a good site for Cinquefoil Skipper (P cirsii) in SE France today. With such a beautiful red underside you can understand the Dutch name Rood spikkeldikkopje ('Red Skipper').

On a mud-puddling site hundreds or even thousands of butterflies can gather for minerals (mostly males). During 40 years of butterflying I have see quite a few, but this site in SE France can now be added. Mostly Chalkhill Blue (P coridon).

Lots of butterflies today on the Col de Champs in SE France, inc A paphia valesina. At least 35 species on 100m or so.

Is 2025 (red lines) a good butterfly year? Yes, on Dutch Butterfly Monitoring transects there are more butterflies than in 2023 and 2024. Numbers almost exactly equal 2022. But look at the 1990s. Compared to then it is a poor butterfly year. Shifting baselines!

In my area on S Veluwe (NL) a new generation of Queen of Spain Fritillary (I lathonia, kleine parelmoer) is out, I counted 13 in a 15min count (plus a Swallowtail P machaon, koninginnenpage). Also many Meadow Brown (M jurtina, bruin zandoogje), top of summer.

A good year for all four Pieris-whites on Dutch Butterfly Monitoring transects. The Southern Small White (P mannii, scheefbloemwitje) seems to be having its highest numbers so far, but also Large and Small White (P brassicae and P rapae) can be seen in large numbers.

For those who just start with butterflying it will be hard to understand just how abundant the Essex Skipper (T lineola, zwartsprietdikkopje) could be on Dutch butterfly monitoring transects in the 1990s.

So far the mean number of butterflies per 1000m on Dutch Butterfly Monitoring transects mirrors 2019 and 2022. But also clear we will have more that 2023 and 2024, which were the worst years since 1990.

Zwart- en geelsprietdikkopje lijken veel op elkaar, maar de mannetjes zijn relatief makkelijk uit elkaar te houden via de geurstrepen op de voorvleugel bovenkant: lang en niet evenwijdig aan de aders bij de geelspriet, kort en evenwijdig aan de aders bij de zwartspriet.

Queen of Spain Fritillary (I lathonia, kleine parelmoer). Unexpected find at one of my transects (NL). The species suffered from the wet 2024 and vanished from many inland sites. Apparently the present warm and dry weather makes it time for a come-back.

Ilex Hairstreak (Satyrium ilicis) today at an airbase in South NL. With five people we found six. This once widespread species declined with >90% since 1990 in NL and has now become rare and local.

The 'June-dip' was at the end of May this year (red line) on Dutch Butterfly Monitoring transects. Graph shows mean number per count per week per 1000m transect. Meadow Brown (M jurtina, bruin zandoogje) is emerging and the Pieris-whites are starting their second gen of this year.

The first half of June is a bad period to look for butterflies in the northern half of Europe, with the spring generations gone and the summerbutterflies not started yet. The map shows the number of butterflies per 1000m on transects and 15min counts in Europe (www.butterfly-monitoring.net).

Already lots of Silver-washed Fritillaries (A paphia, keizersmantel) in this woodland in Bourgogne (F), all males.

When warnings of Insectageddon were issued a few years ago, there was widespread denial. Less so now. It's devastating. www.theguardian.com/environment/...

Our earliest (May!)record of a Large Skipper (O sylvanus, groot dikkopje). Together with some also very early Heath Fritillaries (M athalia, bosparelmoervlinder) and old Sooty Coppers (L tityrus, bruine vuurvlinder) still some butterflies around on the Veluwe.

Numbers now very low on Dutch Butterfly Monitoring transects: the early spring butterflies are over, the summer butterflies haven't really started, and we exterminated the species which could be flying now (as this Pearly Heath, C arcania, tweekleurig hooibeestje, photo from last week in Germany).

General pattern on Dutch Butterfly Monitoring transects this year so far: common and widespread species doing relatively well, rare and threatened species struggling, e.g. low densities of Grizzled Skipper (as last year).

The first time I find Eratophyes amasiella (Oosterse Schone) in the trap in the garden, a really beautiful micromoth. The species was probably accidentally introduced in Western Europe, most likely as a caterpillar or pupa, with logs (wikipedia).

The Painted Lady (Vanessa cardui) is a butterfly migrating each year from Africa to Europe and back in fluctuating numbers. Follow the expansion on 15-min counts (butterfly-monitoring.net/bms-methods) on butterfly-monitoring.net/painted-lady-seasonal-distribution

The Sooty Coppers (Lycaena tityrus, bruine vuurvlinder) are out in my area on South Veluwe (NL), and males occupy high places to chase anything that comes near.

After ten months this Brimstone (Gonepteryx rhamni, citroenvlinder) is more or less over. Mission completed.

Enjoy this great short (9 min) film on the work of Constanti Stefanescu, co-ordinator of the Catalan Butterfly Monitoring Scheme. Such schemes are not only important for the butterfly counts, but also as a social network bringing butterflies to the people. www.youtube.com/watch?v=d__p...

Spring 2025 has been very good for the Map (A levana, landkaartje) on Dutch Butterfly Monitoring transects, recovering after a series of dry years with a large 3rd gen in 2024. However the lack of rain now is also worrying for the next generations.