Wall Brown, Lasiommata megera

Back in February 2018 I reported on how the Wall Brown had arrived in East Lothian and then continued westward across the county. I am pleased to say that the species has continued to do well and has now been recorded over most of the county.

The map below shows sightings up to 2020 and this year it they have been seen right along the coast to the west.

It is interesting how they have tended to move along the coast both in East Lothian and as they have spread up the country.

I moved about 40 miles south of East Lothian last year, but there are no Wall Browns here. They are very common along the coast, but haven't ventured inland. We certainly have a shorter season here and in the spring I notice that plant are up to three weeks behind those on the coast. Possibly the season is just too short for Wall Browns, but I do live in hope that we will see them here soon.

Double Brooders

Last year I tended to take a lot of pictures of butterflies on our land using my phone. I would always have my phone in my back pocket whenever I was working outside and it was easy to take a quick record shot, rather than running to the house to get my camera, only to discover that the butterfly had then flown away!

Imagine my horror earlier this year when I discovered that all my pictures had disappeared from my phone. Luckily Google Photos automatically backs up every picture I take and so I have spent many evenings sifting through them and downloading the better pictures onto my laptop.

Amongst the pictures I was keen to save were some of a hutchinsoni form of the Comma that I saw last August. This is a lighter form of the Comma, Polygonia c-album, which it is thought is a result of the caterpillar developing while the day length is increasing. i.e before mid-summers day.

This form goes on to breed again the same year. Normally, in Scotland, the Comma just has one brood a year. The double brood is more common in England. This is the first time I have seen this form of Comma, but apparently a few have been seen in southern Scotland in the last few years. Possibly another sign of the climate changing, or maybe just a result of the lovely weather we had last spring.

Here is the normal form of the Comma.

And in contrast here is an interesting dark Comma I saw a few weeks later. This gave the impression of being a purple butterfly when it was flying.

Also, in August I found a cluster of Small Tortoiseshell caterpillars.

Here the Small Tortoiseshell, Aglais urticae, is normally single brooded, but further south there are two generations a year. I have never found caterpillars that late in the year and this was definitely a second brood. Again, probably the result of the great spring. I reared one of the caterpillars, which emerged from its chrysalis on 11th September, very much later than the usual early July.

Holly Blues in East Lothian, Celastrina argiolus

This beautiful little butterfly is found extensively across England and Wales but there is only the odd record in Scotland. Most of those are from East Lothian, although they have been recorded in Fife and the Scottish Borders.

I was always aware of a colony on the western edge of East Lothian, but when I checked out Butterfly Conservation’s records for the area, I only found one record from 2013, although I know they had been seen there for many years before that. It just shows the importance of making sure that sightings of any butterflies are sent to the local recorder. Sadly, following a series of cold winters that colony appeared to die out.

For the last ten years, though, there have been single sightings each year from an area around three villages in the north of East Lothian. These have all been from Dirleton, North Berwick and Gullane and I suspect that there is a large private garden somewhere in that area containing Holly and Ivy where a colony of Holly Blues has secretly been living. Those individuals that were seen could all have flown from that one colony.

Despite the efforts of a few of us, we have never found where that colony may have been.

In 2011 there was great excitement, as three Holly Blues were seen on the outskirts of Aberlady. However, despite careful checking of the area since, they were not seen there again.

Then in 2019 some Holly Blues were seen feeding on Snowberry flowers on the outskirts of Gullane, right next to a popular path. I am sure that they would have been spotted in previous years if they had been there. I think the maximum count seen then was 7 butterflies.

A little later in the year a second colony was found a few hundred yards away and a couple of individuals were spotted on the outskirts of the village.

In 2020 we anticipated their return, but we were disappointed that no one saw any in these two locations during the spring. We wondered if these were yet more failed colonies that couldn’t cope with our winter weather. However, I started to receive records from other areas of East Lothian, up to 12 kilometres away. I think we had records of 38 Holly Blues that spring and later in the summer, when the second generation was flying, we had a further 52 records come in, including several from the two colonies in Gullane and from the site in Aberlady where they were seen in 2011.

I would love to find out more about Holly Blues. I get the impression that females must fly from the original colony for up to about 10 kilometres in search of somewhere to lay eggs. This would explain the individual sightings over the last few years and the new colonies that have sprung up around East Lothian. Many of these are in areas that have been regularly surveyed by enthusiasts, so any Holly Blues would have been spotted there in previous years.

Already this spring there have been quite a few records sent in from the areas we found them last year. It will be interesting to see if they expand their range further when the next generation appears in August.

I guess I will never know where the original colony was, but it is great that Holly Blues are now becoming a regular site in East Lothian.

East Lothian Butterflies 2020

For the last few years I have been coordinating the butterfly records from the Countryside Rangers and volunteers in East Lothian and then sending them in to Butterfly Conservation. 2020 was a very unusual year in more ways than one. The coronavirus, weather and my move to the Scottish Borders all impacted on butterfly recording.

After a reasonably mild, but wet winter the weather was wonderful from March until June. Coupled with the good summer of 2019 this resulted in a few early records, such as Small Coppers being seen on the coast near Dunbar on 7th April, the earliest record in Scotland.

Unfortunately in early June we had some very heavy showers and the wet and cloudy weather persisted for much of the rest of the year. I am sure the poor weather later in the summer impacted on the number of butterflies we saw.

The Covid-19 lockdown came into effect in March, meaning that we were not able to travel, other than for essential reasons. Luckily many of the East Lothian Countryside Volunteers took up the request to record the butterflies that they saw in their gardens or while they were taking their daily exercise.

The transects took a real hit, though, as it wasn't possible for people to travel in order to undertake these surveys. Only the John Muir Country Park transect was walked all season and two other transects were walked from July until September. There are normally nine transects regularly walked in East Lothian.

But, thanks to everyone's efforts we received 1,858 ad hoc records of butterflies in 2020, a bit down on the average of 2,200, but much better than it could have been. The number of butterflies recorded varies year on year, but has averaged about 13,000 over the last few years. In 2020 we only recorded 5007 butterflies. Undoubtedly the lack of transect records has contributed to this, but some species didn't appear to do very well last year, particularly those that we normally see in good numbers after June.

Because of all of the variability in 2020, it would be wrong to directly compare the figures with previous years, but there were still some very interesting results.

The spring populations of Large Whites and Small Whites, appeared to do well, but the summer generations were smaller than we are used to seeing. This appeared to correspond with the weather conditions during each generation. The ever-reliable Green-veined Whites, though, did well throughout the year.

After the bumper numbers of Painted Ladies we saw in 2019, it seemed odd that we had so few records last year. In 2019 we recorded 5,395 Painted Ladies, but in 2020 we only had 18 records. The number that arrive on our shores depends on how well they have done in North Africa and southern Europe earlier in the year, but it is interesting to see the dramatic difference there can be each year. You would imagine that with so many returning from the UK in the autumn of 2019 that there would have been a good stock to start the 2020 season with. Possibly there was limited food available in North Africa, maybe the weather in southern Europe wasn’t so good and, of course, we would normally expect to see large numbers appearing on our shores in July, when the weather was particularly rainy here.

The big story of 2020 was Holly Blues. For the last few years we have received one, or occasionally two, records of a Holly Blue in East Lothian. These records have usually been from a 5 kilometre stretch of the coast, leaving us to suspect that there was an undiscovered colony in a large garden or other secluded location in the area. Then in 2019 two colonies were discovered in the village of Gullane, right in the middle of that area.

In the spring of 2020 we we received records from that same general area, but also from further along the coast and from 5 miles inland. Then in July and August we had several more records from all these areas and a bit further afield. By the time we received the last record on September 6th, 90 Holly Blues had been recorded in East Lothian. It was an amazing expansion in their range and most of the sightings were from places which are regularly checked for butterflies so they would have definitely been seen in previous years if they had been there.

Two Large Skippers were spotted, one inland and one at the coast. I suspect that there are more of them around, but they tend to whizz from flower to flower and are often difficult to spot.

There was a mass arrival of Red Admirals at the end of June, but numbers were lower than expected later in the year. I guess the weather didn’t help, but I noticed that many of the caterpillars in my garden were attacked by parasitic wasps and perished. I wonder if the same happened in East Lothian?

However, Peacocks and Commas also seemed to do less well later in the year, suggesting that it may have been more to do with the weather.

In contrast, Small Tortoiseshells had a really good year, which is good to see. There is quite a lot of national concern because their numbers have been declining over the last few years. Let’s hope this is the start of a renaissance for the species.

I only received one Green Hairstreak record in 2020. The Covid restrictions meant that it wasn't possible to check most of the site where they have previously been recorded, which are all quite remote.

It was great seeing Wall Browns continuing to do well. It is ten years since they were first recorded in East Lothian and they can now be found almost anywhere in the county.

Meadow Browns and Small Heaths both appeared to do very well in 2020 and it was surprising to receive so many records, as they are not what you would consider to be garden butterflies.

I didn't receive any records of Northern Brown Argus in 2020. I am only aware of four colonies and three of those are not in places that people would have been able to visit during lockdown. There is a colony on a coastal golf course, where I only saw one Northern Brown Argus in 2019. I hope that they are still there and just weren't spotted by people walking past.

We had 23 species of butterflies recorded in 2020 in East Lothian, which is fantastic given the restrictions we were all under.

I am very grateful to everyone who contributed records last year. I hope it won't be too long before we are seeing butterflies again in the spring and I really hope that restrictions will have been lifted enough for us to be able to get out and see them.

Orange Tips, Anthocharis cardamines

In the autumn of 2019 I was clearing some debris out of the stream that runs through our property when I noticed an Orange Tip chrysalis on a Garlic Mustard seed head that was growing out of the bank. The chrysalis was hanging upside down, as the girdle of silk that would normally hold the chrysalis upright had broken. I thought it looked rather vulnerable, particularly if the water level rose in the stream, so I cut the stem and stuck it into a flowerbed next to the house.

I kept an eye on it and a couple of weeks later I noticed the chrysalis had fallen off the stem. So, I picked it up and put it in a container on a shelf in the garage.

Elsewhere I had noticed two other chrysalises that were hanging upside down on Garlic Mustard seed heads, so I decided to cut the stems and I kept them in the garage over the winter for safety.

I only found one other chrysalis and as this was attached securely to another Garlic Mustard stem I decided that it was probably best left alone.

They remained in the garage until the beginning of April last year when I decided it was time for them to go outside into a little mesh cage under an overhang on our house. Throughout the time that I had them, I occasionally sprayed water onto the chrysalises using a tooth brush.

I have reared Orange Tips in the past, but I had always been at work when they had emerged. In 2020, because of the Covid lockdown I was working from home, so I hoped I would be able to see them emerge.

A couple of days before the chrysalises emerge the colour of the upper side of the butterfly's wings starts to show. This gives a good indication of when the butterfly is likely to emerge and I was determined to catch that moment. I kept a regular eye on them and would check them every hour or so to see if there was any change.

On 24 April I checked the chrysalis as usual and at 11.00am I discovered that it had emerged and fully dried out. At 11.45 it opened its wings and flew a few feet to the lawn where it sunned itself for a few minutes. Then at 11.53 it flew a few more feet onto a Cowslip, where it stayed for over half an hour before flying off.

On 2 May, two days after the second chrysalis had started to colour up, I checked it at 9.25am and there was no sign that it was about to emerge, but when I looked again at 10.45 there was a butterfly sitting in the cage, ready to fly off!

I was really determined to see the last chrysalis emerge, so I checked it at 8.20am and I was amazed to find that I had missed it again and there was a butterfly sitting there. This was long before the sun reached the place where I had the cage.

Interestingly, the chrysalis that I left in the wild failed to emerge.

I will just have to hope I have better luck this year, although I only have one chrysalis!

Red Admiral, Vanessa atalanta

Last June on a lovely sunny day I noticed a Red Admiral, Vanessa atalanta, flying around our hen run, landing on some young nettles, Urtica dioica, that I had previously cut down. Once it had gone I had a look at one particular nettle plant that it had been showing a great interest in and found an egg. Thinking that it wouldn’t have a chance of survival I picked the nettle and put it in some water in the house.

The egg was laid on the 25^th June and four days later I noticed that it had hatched. The caterpillar was a clear green colour with a black head and it remained in the smallest leaves at the top of the nettle, where it weaved a small silk shelter.

On 1^st July I noticed that the caterpillar had changed into the second instar and was now dark with small spines. It was now about 4mm long.

After that it was very difficult to see the caterpillar as it made itself a beautiful tent by nibbling through the nettle stem causing the top to flop over. It then wove the serrated edges of a leaf together to create a little chamber to live inside. It clearly ventured out at night and ate other leaves and on occasion would build itself a new tent.

On 23^rd July I noticed that it had woven itself a little silk pad and had started to hang from it in a J-shape in preparation for forming a chrysalis.

On 25^th July it had shed its skin and was now a chrysalis.

It remained like that until I noticed the colour of its wings became apparent through the chrysalis. It remained like this for a couple of days and then, despite it being in my study on the 10^th August it emerged into a beautiful butterfly while I wasn’t looking!

It was fantastic watching it go through the whole process from egg to adult butterfly. It was particularly thrilling watching it fly off once its wings had fully expanded and dried out. There were a lot of Red Admirals on our Buddleias later in the year and it would be nice to think that they were descended from this particular butterfly.

Back in June on the same day that I saw the Red Admiral laying and egg I also spotted a Painted Lady laying an egg on some Woodland Groundsel , Senecio sylvaticus. It was similar to the Red Admiral egg, but had more ribs. Sadly we had really heavy rain the following day and the egg was washed away. It would have been great to have reared it alongside the Red Admiral.

Northern Brown Argus eggs

In a previous post I talked about my attempts to create a bank of Rockrose as an experiment to see if it is possible to replicate the area up the valley where Northern Brown Argus, Aricia artaxerxes, are found. The first batch of cuttings I took four years ago was a success and they are now doing well, so last year I decided to take some more cuttings so that I could expand the area.

In July I collected several shoots of Rockrose and made a tray of cuttings. Despite checking carefully when I was picking the shoots, once I got home I discovered that there were eggs on two of the shoots. One leaf had two eggs on the underside and another had one egg on its top surface.

So, I drilled a couple of holes in the lid of a jam jar and put the two shoots into water. Unfortunately, Rockrose doesn’t appear to like to grow like this and the leaves quickly dried up. I therefore had to replace the shoots every couple of days.

Six days later on the 25th July one of the eggs hatched and another hatched the following day.

They were incredibly small and remained on the top surface of the leaf, puncturing it and sucking out its contents, leaving small brown marks.

Most books say that the caterpillars feed on the underside of the leaves, but these two caterpillars spent as much time on top of the leaves as they did under them.

It was clear that putting sprigs of Rockrose into water wasn’t working well, so in August I found a small Rockrose plant that had been half dug up by rabbits. I put it in a pot and transferred the caterpillars onto it. This made them even more difficult to find as by this stage they were still less than 3mm long. 

I was hoping to note when they changed instars, but it was really difficult to spot the difference between each instar when they are so small. Also with them being so active, I was never sure which of the two caterpillars I was looking at!! I noticed on the 5th August that one of them was looking greener, so I presume it had shed it skin and was now second instar. On 18th August one of the second instar caterpillars shed it skin and the other did the same on the 28th August.

They continued to grow and I would spot them occasionally as they ventured from under the leaf they were feeding on. Then on 16th September I was unable to find them. I presume, and hope, that they went into hibernation. The pot was still in the house at this time, so it would have been day length that triggered this, rather than temperature.

Later that month I put the pot outside in a mesh cage. The Rockrose was rather depleted of leaves by this time, so I purchased some cultivated varieties of Rockrose and put these pots next to the wild Rockrose. My hope is that the caterpillars will reappear in the spring and transfer onto the new plant. I hope to report back later!