News from the Butterfly Conservation
County Butterfly Co-ordinator for Yorkshire Howard Frost

Howard Frost is Butterfly Conservation's Butterfly Recorder for Yorkshire. As a volunteer, he organises the butterfly recording effort for the whole county and with the help of an enthusiastic team of assistants, draws together the results in an annual report. He also works closely with those volunteers recording the moths, and has contacts with County Recorders in other parts of the country, as well as enthusiasts in Europe.

Frost Report 15th June 2009
The Painted Lady invasion is still going on although now down to a trickle. Most have now settled and in my own experience can be found in almost every 1km square in East Yorkshire. But this doesn't seem to be case all over the county. The northern edges may have missed out. Still, if these immigrants all breed we could see record numbers by August. As they lay eggs on thistles there is plenty of suitable habitat for them to occupy! The current immigration looks like being one of the largest on record and is notable for the length of time it has continued, already over three weeks! And there was an earlier wave came into the south coast of England in mid-April!

Red Admirals have been relatively scarce so far, but there seem to have been more coming in over the last few days as well as lots of migrant moths, particularly Silver Ys and Diamond-backs.

Spring butterflies have done particularly well this year, especially Orange-tips. In fact the latter are still flying in my home area in the far south-east of SE Yorkshire. I saw both a male and a female on 13/06, virtually overlapping with the first Meadow Browns - 3 on the Humber Bank on 14/06. That's quite early for this species, even for our area. But it might have something to do with the fact that we have had less than 2cm of rain since the third week of February and lots of sun!

Common Blues are doing exceptionally well in SE Yorkshire. I counted over 250 during a 1.5km walk along the Humber Bank on 15/06 which is the biggest number I have seen locally for many years. The first Large Skippers are showing well now and we have seen quite a few Walls, although thinly spread.

The 2008 Butterfly & Moth Report has been slightly delayed at the printers and is now due in early July. Copies ordered via myself should, hopefully, be mailed out in the second week of July. Copies can still be ordered via myself with cheques payable to Butterfly Conservation Yorkshire for £11.50 (inclusive of post & packing) and sent to me, Howard Frost, 10 Chellsway, Withernsea, HU19 2EN.

Frost Report 27th May 2009

The current bank holiday arrival of Painted Ladies is turning out to be big, really big. Reports have indicated tens of thousands streaming across the English Channel and North Sea from Kent to Yorkshire, with individual reports from the south as high as 12,000 in 2 hours! By the time the wave reached Yorkshire towards last weekend, the butterflies were well spread out and easily missed as they were travelling across the countryside at such a high speed. On Bank Holiday Sunday and Monday my wife and I criss-crossed the Holderness countryside, east of the Yorkshire Wolds, and got the impression of a steady stream always flying north-westward. Spurn recorded up to 90 at the weekend but the problem with counting was that the butterflies appeared to be flying in from the sea along the whole coastline and were so spread out that getting any feel for the real number concerned was virtually impossible. Yesterday, 26-05-09 the wind changed from the SE, which had been ideal for the migration, to NW which meant flying into a strong headwind. The movement stopped. But then we found individuals in virtually every 1km square we visited, and all had their colours washed out. This is typical of butterflies which have flown directly from the edges of the Sahara Desert where the Painted Lady breeds throughout the winter. The cause is thought to be a result of living in an area where blown sand abrades the wing scales, although another theory is that the colours become bleached due the strong desert sunlight. Perhaps both have an effect. The key thing is that only the butterflies from North Africa come to us in this faded state. Later immigrants, which result from breeding on the continent, are much fresher. Clouded Yellows have also been coming in further south as revealed in the Cambridgeshire and Essex Butterfly Conservation Branch website. We have also noted a few Red Admirals beginning to appear, as well as lots of Diamond-backs and a few Silver Ys. We have also been pleased to note a good emergence of Walls and Common Blues in our area. With the promise of another fine weekend, do try to get out and record what is going on in your area. Remember, as this is the final year of the current five-year butterfly recording cycle, we need as many of your records as possible. And there may be Clouded Yellows out there waiting to be noted down. Good Luck!!

Frost Report 15th May 2009
Spring has seen very variable conditions across the county with long dry spells in some areas and torrential rain and showers in others. In my home patch, the area to the far south-east of the county (Withernsea to Spurn), May 15th brought us the first substantial rainfall since February 20th! We have been seeing butterflies fairly regularly since the end of February. By contrast, Terry Whitaker (our VC64 records Co-ordinator), who lives in the western Pennines where it has been notably and frequently wet, only saw his first butterflies of the year at the end of April.

In the Vale of York, Orange-tip butterflies have been flying since at least the 3rd week of April, whereas on the coast, the onset of cold easterly winds dampened down much of the butterfly activity and delayed the appearance of the Orange-tip by several weeks, with first records on May 7th.

My wife and I have criss-crossed E Yorkshire over the last four weeks and found Small Tortoiseshells widespread but worryingly thin on the ground. By contrast, Peacocks seem to have had an excellent winter survival rate as indeed have Brimstones which seem to be more common and more widespread than ever. Dingy Skippers appear to have peaked on the Wolds over the last week and we counted some three dozen on each of two sites, suggesting it has been quite a good year for this increasingly threatened species. It flies throughout May and into June and we would be very interested in any other Yorkshire records. It is a butterfly of undisturbed grasslands with plenty of bare patches. It is probably quite common along the cliffs (and maybe the old railway track) between Scarborough and Whitby, but few people get out there to record it at this time of the year! And being the last year of the current five-year national butterfly survey we need as many records as possible!!

LATEST UPDATE
An unexpected arrival of butterfly and moth immigrants reached Spurn last Friday 15/05/09, including 5 Painted Ladies, a Dark Sword-grass, a number of Diamond-backs and Silver Ys, plus a rare Purple Cloud – the 23rd record for Britain!! (Thanks to Barry Spence for this news.) My wife Christine also trapped single Diamond-backs in Withernsea on 17th & 18th May. The large low-pressure system currently over Britain is dragging in streams of air from the Mediterranean and pulling them across France and on into Britain. The result has been some viciously stormy weather over France with hailstorms which have devastated large areas of vines in the south. It is quite amazing that such fragile insects as butterflies and moths can utilise conditions like these to get themselves further north. Immigrants have also been noted coming in from a sea crossing at Dungeness in Kent. HMF

Frost Report 1st January to 15th April 2009
The Frost Report opens each year when the previous year’s Annual Report on Butterflies and Moths is completed and on the way to the printers. As its Editor and much to my relief, that happened yesterday. Another 112 page booklet with 16 pages in colour, is on its way, this year entitled: Yorkshire Butterflies and Moths 2008. It should be ready about mid-June. It goes out to Butterfly Conservation members free as part of their membership package. A few extra copies are available to non-members at £11.50 inclusive of packing and postage. Orders are available from me: Howard Frost, 10 Chellsway, Withernsea, HU19EN and payable to Butterfly Conservation. It is advisable to order now in advance as most of the spares are accounted for before publication.

The year so far has started with a cold winter coming to an end in mid-February and very few Dec/Jan butterflies about. But from late February onward, in a long, dry, often sunny, high-pressure weather period, there has been a steady increase with no fewer than 13 species recorded in Yorkshire so far. The recent wet spell has already given way to a large high pressure to the north which looks like giving us a sustained period of easterly winds, good for early bird migrants and possibly for butterflies and moths as well, although we need to see the fog clear the east coast before conditions are really favourable.

Today (as last Friday) Yorkshire finds itself at the tip of long plume of warm air coming from N Africa and crossing Spain and France before reaching us. Last Friday that warmth with southerly winds pushed our coastal temperatures to a surprising 19.5 degrees C. Today, that plume will be turning west over the near continent and approaching us from the east, so coastal areas will still feel some chill from the cool sea.

Small Tortoiseshells and Peacocks seem to have been fairly widespread through March and into April, although cool nights have meant that it has only been warm enough for them to fly for short periods each day. Other species seem to have been thin on the ground and dependent on the pupa (chrysalis) or adult being somewhere warm and sheltered during hibernation. The biggest surprise was the report of a Painted Lady at Flamborough on Feb 22nd. We don’t usually expect this migrant from N Africa to reach us until May/June time. Midwinter arrivals to the S Coast of England are not unknown, but this last winter has been exceptionally cold on the continent right down to the Mediterranean coast, with northerly winds the norm. I discussed this with Richard Fox who co-ordinates Butterfly Conservation’s recording and although he thought it rather an unlikely record he did mention that a similar record had been reported from Sussex around the same time, and this had been dismissed as a probable mis-identification, especially as it had only been seen flying by and not at rest. It is thought that this species is unable to survive our winters as it cannot hibernate as an adult. However, there has been one example in recent years where an egg laid late in autumn went through its various stages in winter and produced a butterfly in spring. But it was in a sheltered, mild situation on the S Coast, and in a mild winter. So this remains a puzzling record!

Butterfly numbers should rise over the next few weeks and as this year is the last recording year in the current national five-year survey, we hope that many of you will be making an extra effort to record as widely as possible and send your records to your VC Co-ordinator as listed elsewhere in this website. Thanks!! Last year, in spite of the weather, we had over 30,000 records sent in. My dream is to hit the 50,000 mark one year! Please help make it 2009!! HMF

Frost Report Update to November 2008
I must apologise for a long break in producing these periodic reports. Sometimes life gets in the way of one's voluntary interests! From late August to November a whole cluster of events including three weeks of building work- and the consequent tidying up - (not to mention the complication of BT taking down our phone line and forgetting to put it up again for three weeks!) - all this militated against my getting out to record what butterflies were about, or to write a few words to keep this column up-to-date.

By September, I was hard pressed to complete our latest edition of the Yorkshire butterfly and moth journal, Argus for which I am editor. That was also complicated by the transferring of its production to a new computer. But at least the journal is now complete and has been sent out to members. Usually, we have a few copies spare, which we sell to help raise funds, but this time our membership has been rising so fast that there are no spares at all. At the last count we had 767 members which is great.

The new edition of Argus, No 55, has some fascinating articles including a major addition to our report on Alfred Tetley covering his observations of Large Heath on the N York Moors in the early 1900s. There is also an article on setting out to make your own moth trap and another on the moths of the Yorkshire Air Museum site at Elvington. There are also two reports about the dramatic spread of the moth which is attacking our Horse Chestnut trees and causing their leaves to turn brown in mid-summer. It is worth being a member!

Since my last report, it is clear that July and August were pretty poor months for our butterflies and moths. Even so there were one or two surprises, with Camberwell Beauties recorded in Muston (near Filey) and in Withernsea (but not seen by myself!). These had almost certainly flown in from Scandinavia. Common garden species like the Peacock and Small Tortoiseshell usually appear in mid to late July and peak in early August. This year most of them very sensibly failed to emerge until four or five weeks later with Small Tortoiseshells on the wing until October. There is a strong suspicion, backed by observations of this species flying in from the sea, that we had a sizeable immigration from the continent, perhaps also from Scandinavia. Numbers were much higher along the Yorkshire coastline with 30s and 40s seen in gardens, compared to only relatively small numbers seen on inland sites in the west of the county.

In recent years, the end of the butterfly flight season has extended from around mid-October to mid-November. But this year, the cold spell towards the end of October seems to have brought an earlier end to the season to all except a few hardy Red Admirals. So now, it's heads down to receive and process all the 2008 records and to prepare the next Annual Lepidoptera Report for the county. Although it won't be available till next June, some of us will be working flat out for most of the winter to achieve that goal!

Have a good Christmas, and a Happy New Year! Let's hope 2009 will give us some better weather to allow our many stressed out species some recovery time. And if you haven't sent in your 2008 records yet, you need to work fast. Your VC Co-ordinators should be sending out their species breakdowns to our Species Co-ordinators before or by the end of November. If your records aren't available to send off then, they will be still welcome, but they will not be in time to be included in the Annual Report!

Frost Report Update to 17/08/08
During the last week the odd sunny days in a stream of wet ones have at least encouraged an upsurge in butterfly numbers. It has been particularly reassuring to see up to a dozen Peacocks in the garden as well as lots of whites. My wife has also been catching up to 20 Silver Y moths in her moth trap this week. If you only look at what is happening in your garden, it is easy to be misled, as this may be a very local event. In order to better gauge what has been happening across the countryside my wife and I did a 100 mile 'transect drive' across East Yorkshire on Friday, recording along roadside verges on the move. Our route took us through Holderness and the N Wolds. It was my job to concentrate on driving safely whilst my wife did the recording. As far as practical, we followed country lanes where there was little traffic and it was possible to go fairly slowly.

There aren't too many days in the year when butterflies are plentiful enough to make this approach to recording worthwhile. Friday proved to be ideal and we recorded butterflies in no fewer than 118x1km squares which I think is the most we have ever covered in a day. As might be expected, the commonest species were Small and Large Whites. Numbers of both these species seem to have been going down in recent years, so even though they are pests, we were pleased to see so many. Large Whites often fly in from the Baltic area in August and such a possibility seems to be corroborated by an arrival of bird migrants along the coastline as both would use the same wind and weather conditions to make a North Sea crossing.

On occasions where we stopped briefly to further investigate a promising verge we were surprised to find quite a few Meadow Browns still flying, and on two verges we spotted fresh Painted Ladies, our first sightings in Yorkshire for this year. Small Tortoiseshells were relatively scarce: in all we spotted just 7 compared to the 79 Peacocks we counted along our 100 mile transect. However, all the Tortoiseshells were fresh indicating that they had just emerged. Perhaps we will yet see more emerging very much later than normal. In all, we spotted 14 species, an indication of how important our roadside verges are for butterflies.

Frost Report Update to Aug 10th 2008
Following my last report from France, I spent another 2 weeks in the NE quadrant of that country and the butterfly scene remained much as previously described. We failed to find about 10% of the species we normally expect in that area – especially amongst the Blues. Numbers of most species were way down (except for the Browns – especially Meadow Browns), and we only saw 1 Clouded Yellow (when we expected 100s if not more), and 3 Painted Ladies (which suggests a very low level of immigration). There were many buddleias out in parks, gardens and alongside road verges at the entrance to villages competing in the annual 'Villages Fleurie' competition, but almost all were empty of butterflies. Particularly striking was the complete absence of Small Tortoiseshell, the first time in over 20 years of visiting this region that we failed to see a single one! Watching the daily TV weather forecast, it was clear that the northern half of France was suffering from the same cool Atlantic air-stream as much of Britain, and the clouds above our heads were then turning N and NW and often heading straight for Yorkshire! Two hundred homes were destroyed by a tornado in N France a few days ago. Not the weather to encourage much migration, especially with so few migrants showing signs of successfully breeding and wanting to head further north!

On our return to Yorkshire during this last week we found our buddleias still out, but not much on them. Just a few Large and Small Whites, 4 or 5 Peacocks and the odd Red Admiral. 2008 is simply not a year for numbers. My wife, Chris, managed to spot 2 Small Tortoiseshells in our allotment a day or two ago. A record!! Given some better weather things could still change. Small Tortoiseshells in particular seem to be appearing ever later in August with each passing year. But unfortunately, the current outlook remains poor. All the more reason for noting down and sending in the records which do occur!

27th July 2008
From France on 22nd July - in the High Marne, a region of rolling limestone hills a bit like the Yorkshire Wolds. If you think of France as a square, the High Marne is just to the north east of the centre. For a week we've had cool cloudy weather brought by the same north west airflow affecting Britain. All the locals have been asking "Where is the sun this year?". At least around the Mediterranean it has got warmer and sunnier but with an almost constant Mistral blowing at 50-80 kph visitors have been finding it most unpleasant. A 50mph gale at 30 degrees C blowing from the north does not encourage butterfly or moth migration! Not surprisingly we've only seen one each of Clouded Yellow, Red Admiral and Painted Lady when, in other years, we've seen many tens or even hundreds (we've been surveying this area annually for over 20 years so are well acquainted with most of the local butterfly hotspots).

In summary, there are very few butterflies about at all and just as in Britain, those that are flying in any numbers are the browns, particularly Meadow Brown and Gatekeeper. The reason for this is that because the butterflies are brown coloured, they can absorb the available heat better than most. With night temperatures down to 8 degrees C or lower - remarkably cold for central France - they need that ability. Hopefully things might be changing both here and in Yorkshire as a large high pressure has started to build. This afternoon the clouds began to melt away and Meteo France is promising us at least a week of sunshine! Let's hope that they are right.
We may see some butterflies yet!

29th June 2008
Frost Report Update: 28/06/08 – I keep trying to be optimistic about this summer and its potential for seeing moths and butterflies. But each bit of news which reaches me persuades me that it is not to be! Last year, with all its heavy rain and floods, is now reckoned to have been the worst in 25yrs for the Lepidoptera (ie the butterflies and moths). This year shows every sign of suffering from the fewer eggs that were laid last summer as a result.

At least, the last two weeks have seen better moth numbers caught in our trap (in Withernsea, SE Yorkshire, not far from Spurn). On some occasions my wife has counted over 70 individuals of up to 19 species. Our house in the middle of an estate of over 100 dwellings and I am always surprised how many moths actually visit our back garden, particularly in a year when there have been hardly any butterflies visiting.

We continue to catch a handful of common immigrants like the Silver Y and Diamond-back, just as there continue to be a few Red Admirals around in the countryside, but my daily look at the continental weather forecasts, shows that weather over France has been far too changeable and cool to encourage much migration. The northern half of France has been in the same run of cool westerlies as ourselves, and only over the last 5 days or so have the temperatures around the Mediterranean begun to creep over the 30ºC mark at the hottest part of the day.

A friend who went walking in the Pyrenees two or three weeks back, hoping to see some of the rarer mountain butterfly species was taken aback to find high level paths still blocked with snow. He usually goes to the same area annually and has not experienced this before as late as June. Strange, in a year when scientists expect the Arctic Ocean to completely unfreeze for the first time since before the onset of the last ice age!!

A quick trip across the Yorkshire Wolds yesterday (June 27th), on a cloudy bright but windy day, revealed not a single butterfly flying. We took a brief walk across Millington Pastures, hoping to spot an early Marbled White, but no, nothing. We also visited our BC nature reserve at Elvington Air Museum where we went to finish off the first phase of the butterfly garden we are creating. It's a tiny garden, between two buildings, and all our planting is in pots. The idea is to link it through notice-boards to our three-acre nature reserve nearby. A quick look around the reserve revealed a dozen or so Meadow Browns, and a mating pair of Ringlets. Both these species should soon be common and widespread across the county, especially on road and track-side verges. A single Large Skipper was the only other species we had on the site, and indeed, these were the only butterflies of the day. (Please note the reserve is not yet open to the public, probably not till next year, and then only to paying visitors to the Air Museum.)

It remains a fact, that in the prevailing windy conditions with only fleeting periods of sunshine, you need to hunt out very sheltered sites which catch the available sun if you want to see any butterflies at all. We should be on the threshold of 6 weeks of maximum butterfly numbers, but unless we get more sun and less wind, the year is going to end up as no better than last year.

One bit of excitement for observers across the south and central parts of England this year so far, has been the number of Large Tortoiseshell sightings. Most occurred during that cool but sunny spell we had in April when winds were blowing from the east. That suggests an east European origin for such an arrival. There were also a handful of Camberwell Beauties recorded at the same time. If any of the Large Tortoiseshells managed to breed on arrival in England, their offspring will start to appear around now and may fly into the autumn before going into hibernation. During their flight period it is possible some could head further north! If anyone thinks they have seen one please note down full details and ask your VC Co-ordinator or our Webmistress for a rare species report form and return it accordingly. Thanks!!

7th June 2008
This last week I picked up the Annual Report from the printers. Copies are available from me at £11, payable to Butterfly Conservation Yorkshire. Sorry the price has gone up a bit, but its quite a weighty booklet and costs over a £1 to mail out. Still, it's excellent reading!

At last things seem to be improving although butterfly numbers across the county remain low. However, there is often a lull between the species which appear in spring and those which come out in summer, and that lull is longer if we get a spell of poor weather. At least we are seeing some immigrants arrive, with Red Admirals and Painted Ladies at Spurn, although no large numbers as yet. Perhaps not surprising with all the turbulent weather being experienced in France where central parts have had it exceptionally cold towards the end of this week, with temperatures ten or more degrees below average. I note from the website that a Painted Lady also reached as far north as Scarborough.

Immigrant moths have also been appearing in Yorkshire with up to 50 Silver Ys at Spurn and quite a lot of Diamond Backs. Spurn recorder Barry Spence has already notched up a new moth species for the county: Celypha rivulana, a tortrix moth. There has also been a local report of a Humming-bird Hawk-moth. General moth trap counts have been rising steadily this week and as tonight is National Moth Night the indications look favourable with some improving weather. In fact, it looks like the airflow will be coming in from Eastern Europe, which could make it extremely interesting.

Back to the butterflies, our typical spring species the Orange-tip and the Dingy Skipper are just about finished, whilst Common Blues and Small Heaths are beginning to appear. I had double figures of both on a Wolds site this week. On the other hand I have yet to see a Large Skipper although a few have been recorded elsewhere. This species is usually out and about in the SE of the county in the last week of May, but has evidently been held up by the cold weather we have had so far. Still, the signs are there. Summer could be approaching! Good moth-ing this weekend!!

24th May 2008
Apologies for a longer than planned break in these notes. I've been coping with builders! No news yet about the forthcoming 2007 Yorkshire Lepidoptera Report. I'm expecting a call from the printer any day.

From my perspective in the SE of Yorkshire, the butterfly season has been unusually slow to get going due to the cold east winds which have now been blowing for 23 days – a remarkably long period. Whilst there have been some warm days inland, coastal temperatures have only occasionally been above 12ºC and even then only for a short time in the day. At least there has been a lot of sun, but the wind has often been too strong for butterflies. In such conditions you have to be a detective and visit suitable habitats you know will be open to the sun but sheltered from the wind. That's where you will find the Orange-tip and the Green-veined White at the moment. There are also worn looking Peacocks and Small Tortoiseshells still about and I saw my first Small Copper last Thursday on our Elvington nature reserve near York.

On the continent it has been relatively cool around the western Mediterranean with day after day of thunderstorms across parts of Spain and much of France, although it has been much warmer in N France than in the south! SE Spain is becoming a desert with virtually no rain for months. Reservoirs are empty and water is being imported from France by the boat-load. Shrivelled vegetation is not much good for butterflies! One vigorous storm over S France left 15cm/6inches of hail on the ground. Not much good for migratory butterflies or moths even if they are trying to shelter! At least one Painted Lady and one Red Admiral reached Spurn on May 13th. They probably arrived in England with the wave previously reported. In N Europe temperatures have been slow to rise, with heavy snow in parts of Sweden. We really need some sunny calm weather!

3rd May 2008 at 9am
My predictions for last weekend turned out quite well. Unlike much of the county, and contrary to the forecast (!). the SE corner near Spurn, where I live had two quite sunny days although with cooling breezes off the sea. The French forecasters were also spot-on about the surge of warm air moving northward from Africa through France. This did indeed bring a wave of Painted Ladies northward reaching as far north as the S coast of England and apparently, according to the BBC4 project detailed elsewhere on our website, a Painted Lady sighting was made in Yorkshire.

Painted Ladies began to arrive in Spain in March and April and have begun to breed there. Where conditions are warm enough, the breeding cycle for this species can be as short as 6 weeks, so that could lead to a further wave moving north from Spain in the not-to-distant future – but always, weather and winds permitting!

The long Bank Holiday weekend across France looks fairly settled and sunny – with maximum temperatures ranging from 19ºC in the N to 28ºC in the S, where night temperatures are expected to remain high at 13ºC or above. This looks favourable for butterfly and moth migration, although the unstable conditions across Northern England may mean we don't see the results this far north, at least, not until later in the week.

Overall, the butterfly season in Yorkshire seems to be getting off to a very slow start. The hibernating species like Peacocks and Small Tortoiseshells are in evidence, but reports suggest that sightings are very patchy. Butterflies emerging from overwintered eggs and larvae are still scarce, but warmer weather promised for the coming week might encourage a change. When you are out and about searching for butterflies at this time of the year, remember they need warmth and nectar. The biggest nectar source in spring is the dandelion. So on any warmer days, look at patches of dandelions that are in sheltered, sunny positions and you will almost certainly spot a butterfly! Another good source of nectar is the May blossom (ie the Hawthorn flowers). You have to look quite closely to pick out white butterflies like the Green-veined White nectaring on white flowers!!