Of Caterpillars and Chrysalises

So far this year has been amazing for butterflies, but not only in their adult form. I also seem to have come across quite a few eggs, caterpillars and chrysalises.

It is always fun searching for Orange Tip eggs and caterpillars on Garlic Mustard and Cuckoo Flowers. This year they seemed to be on just about every flower spike I saw. This is a group of freshly laid eggs on a Cuckoo Flower.

In a couple of days they turn bright orange. I followed one egg with interest, which had been laid on a Garlic Mustard near the house. This was the caterpillar a couple of days after it had hatched.

The egg hatched on 11 May and I watched it develop until the 17 June when it formed a chrysalis. This is another caterpillar preparing to form a chrysalis.

And another one that unusually is about to form a chrysalis head down.

This is the chrysalis of the caterpillar I reared. It seems strange that it will remain in this state until April next year. 

On 13th May I saw a Green-veined White laying eggs on the leaves of a Garlic Mustard plant.

The eggs hatched on the 21st May and the caterpillars developed until the 30th June when they formed chrysalises.

On the 9th July both chrysalises emerged.

I have found three batches of well developed Peacock caterpillars amongst the nettles here. I haven’t noted the dates of any of these, as I didn’t know when the eggs were laid, or when the caterpillars formed chrysalises. However, on 3rd July I was demolishing an old shed and discovered a mature Peacock caterpillar on a piece of wood I had ripped off. Luckily it wasn’t injured, so I put it into a mesh cage, where it crawled to the roof and hung in a “J” shape.

Two days later it was still hanging there, but I noticed a 3pm it had moulted and formed a lovely green chrysalis.

This changed colour over the next few days and on 22nd July it emerged.

Sadly, it didn’t stick around for an open-wing photograph!

On the 5th July I was walking up our drive when I noticed a Red Admiral caterpillar crossing in front of me. Of course I collected it up and put it in a cage, where it immediately went to a Garlic Mustard plant and started stitching together the edges of a leaf to form a tent. The next day I noticed it had formed a chrysalis. I wasn’t very hopeful of a positive outcome, as I thought it unusual to find the caterpillar out in the open like that, as they usually hide away inside leaf tents. However, on the 22nd July it emerged, the same day as the Peacock. 

It was a lot more cooperative and allowed me to take some pictures of it before it flew off!

I have seen a lot of Red Admiral caterpillars and chrysalises in the nettles in our garden. There are a lot of adults flying around so hopefully they will soon be joined by more.

Orange Tip Chrysalises

I used to always think that it was best to leave nature to look after itself, but after watching a number of caterpillars being washed away in heavy rain or eaten by birds and chrysalises being nibbled by mice, or just disappearing, I now think that maybe butterflies could do with a helping hand.

Over the winter I spotted a number of Orange Tip chrysalises on Honesty and Garlic Mustard stems. So I carefully cut the stems and put them in a mesh cage outside, but under cover.

They have been sitting there for about seven months until recently I noticed they started changing colour. Six of the chrysalises were straw coloured when I found them and two of them were green. However, half way through April I saw that they had all turned into more of a brown colour.

Then at the end of April I saw the tell-tale colour of the wings starting to show.

Two males emerged on 2nd May and flew off to join their friends.

On 3rd May a female emerged. It wasn't a particularly nice day and when I opened the cage to photograph her, she crawled onto my hand. After a while she flew off and landed in the grass. It started raining after that and in the evening I went out and she was still there. So, I popped her back into the safety of the cage.

The next day it rained all day and another female emerged. I left them in the cage and they sat on their stems not moving. After two more days of horrible weather I decided to dig up a Dandelion and put it in the cage for them to feed on. As soon as I coaxed them onto the flowers they started drinking water droplets off the petals. They remained on the flower and were still there the next morning.

Then the sun finally appeared at lunchtime and I was able to lift the pot out of the cage. They made a short flight onto the lawn and shortly afterwards flew off. I was so relieved that they had managed to survive four days of dull, rainy weather.

About 45 minutes later I was around the other side of the house and I found a paired couple of Orange Tips. I was able to identify one of them as the female who had spent the previous four days sheltering from the rain!

Over the next ten days the remaining four chrysalises all eclosed and they were all females. In fact it has been an interesting year for Orange Tips. I have never seen so many females. Normally, I would say 1 in 10 Orange Tips I see are female, but this year over a third of them have been female.

Some Orange Tip Observations

Although I believe that it is best to leave nature to do its own thing and not to interfere, I sometimes I think it could do with a helping hand. The spring of 2020 was lovely, but the weather took an unfortunate turn for the worse in June.

In April and May of 2020 there were a lot of Orange Tips flying around and I found loads of eggs and caterpillars. Unfortunately, we had a lot of heavy rain in early June and most of the caterpillars I had been watching disappeared. After one particularly heavy shower I could only find one caterpillar, so I popped it on a Garlic Mustard plant that I had in a pot and put it in a mesh cage for safety.

On 27th June the caterpillar attached itself to the seed head with a girdle of thread and formed into a J-shape. It stayed like that for 3 days before shedding its skin and forming a chrysalis.

I kept the chrysalis in a mesh cage under an overhang of the house. It remained there all winter and eventually emerged into a butterfly on 11th May 2021. I was surprised as this was a dark cloudy morning and only 10 degrees. However, I had noticed its colour change over the previous week, so possibly it couldn't delay the process any longer.

As each Orange Tip's under wing pattern appears to be unique I was able to photograph any I saw and discovered that my Orange Tip was still living on 24th May. It had survived though a horrible period of weather with several periods of really heavy rain.

I often wonder if butterflies can survive heavy downpours or prolonged periods of rain and this one proved that they can. I have also wondered when I see an Orange Tip if it is the same one that I had seen the previous day, or if it is a new one that has flown into the area. Checking through the photographs I took this year, I have identified at least 28 different Orange Tips and only a few of them were seen on more than one occasion.

This spring I was pleased to see plenty of Orange Tips flying around. There were so many that quite a few Garlic Mustard seed heads had more than one egg on them. This is unusual, as it is thought that Orange Tip caterpillars are cannibalistic. I noticed two Cuckoo Flowers growing on the edge of our pond which were proving very attractive to female Orange Tips. When I checked one plant had seven eggs on it and the other had nine. These are really small plants and I find it hard to believe that there is enough to eat in one plant for just one caterpillar. 

A few days later I checked and the eggs had all hatched. I kept an eye on them and then suddenly on day 8 all the caterpillars were gone. I don't know if they were eaten or if they all decided to go and look for something more substantial to fee on. I think I will try to grow a Cuckoo flower in a pot next spring and see if I can attract an Orange Tip to lay an egg so I can see if the caterpillar stays on the plant.

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!

East Lothian Butterflies 2019 Part 1

There was a very clear correlation between the weather and number of butterflies seen in East Lothian in 2019. After a reasonably mild winter there was an unseasonably warm week at the end of February with temperatures reaching 16 degrees. Then it was cold again until the end of March. At the end of April we experienced an even warmer week with temperatures of 26 degrees. However, we still experienced a few hard frosts in May. The remainder of the year was quite reasonable, but it was interspersed with very heavy rain showers. The butterfly season ended abruptly at the end of October when the weather turned cool and wet.

Other than a couple of hardy Peacocks that appeared in January, the warm week in February brought out a flurry of species. We had seen seven species before the end of February, which must be a record for East Lothian. Things then went very quiet until the third week in March when the butterfly season truly started. Most species did very well in 2019, probably as a result of the very good weather in 2018 allowing the early stages of the butterflies to survive in good numbers. However, from July through to September there were occasional very heavy periods of rain which had a dramatic impact on butterfly numbers.

Despite having fewer people recording butterflies than the last few years we had a record 20,598 butterflies recorded in 2019 (16,875 in 2018). This was helped considerably by the enormous number of Painted Ladies that arrived on our shores in June and July, but even without them we had almost as many butterflies as in 2018.

Peacock, Aglais io

The first butterfly recorded in East Lothian in 2019 was a Peacock seen at Aberlady Local Nature Reserve on 11th January. A second Peacock was seen at Levenhall Links three days later. Peacocks have been recorded in increasingly high numbers over the last seven years, with 2019 being the best year yet. Numbers peaked in mid August, but then dropped very quickly again to single figures by the start of September.

Small Tortoiseshell, Aglais urticae

The Small Tortoiseshells waited until the warm week in February to show, with the first record being on the 17^th. They have been declining in numbers over the last few years. However, 2019 saw a bit of a revival in numbers when the new generation emerged towards the end of July. As usual, they quickly disappeared with many of them heading into hibernation surprisingly early in the season.

Comma, Polygonia c-album

The number of records of Commas has gradually been increasing since they were first recorded in East Lothian in 2001. However, they declined significantly 2016 presumably as a result of the lousy summer. Since then they have been picking up and in 2019 the recovery continued. The first Comma was seen on 25th February and, like the Small Tortoiseshell, their number peaked for a week at the end of August and then very quickly they disappeared. It will be interesting to see how many return next spring after their hibernation.

Painted Lady, Vanessa cardui

The big story of 2019 was the arrival on our shores of an enormous number of Painted Ladies. These came in two waves. The first at the beginning of June when we were amazed at the number of Painted Ladies being seen. But that was nothing compared with the number that arrived at the end of July when they were seen in their hundreds. Some of these would have been the young of the previous arrivals, but most of them were seen flying in from the sea. They were also noted flying in a very

definite westerly direction and records were received from all over Scotland including the Outer Hebrides.

I was interested to learn that Painted Ladies had done similarly well in the USA in 2019. So, on both sides of the Atlantic conditions must have been just right throughout the lives of four or five generations of butterflies.

I received records of 5395 Painted Ladies in 2019, a big difference from an average of about 80 over the last six years.

Speckled Wood, Pararge aegeria

The exceptionally mild week in February also brought about a remarkably early record for the Speckled Wood. In fact two were seen on February 26th basking in the sun on the coast at Prestonpans. There was another record on 22nd March. We normally wouldn't expect to see a Speckled Wood here until the middle of April, which is when we started to see them again in 2019. I can only imagine that the three early records were individuals that had benefited from the long summer of 2018 and had formed chrysalises late in the autumn.

The spring populations appeared in higher numbers than in previous years and I was expecting to see bumper numbers later in the summer. However, the heavy rains that we experienced appeared to knock Speckled Woods quite hard.

There were fewer Speckled Woods recorded in 2019 than in the previous year, but they are still doing well in East Lothian.

Small White, Pieris rapae

After such a great year for Small Whites in 2018 I was expecting to see great things in 2019. And it was a good year, but just not as good a year as last year! In 2018 we had records of almost 3500 Small Whites, but in 2019 we recorded 950. However, this is still good when compared with the average for the previous five years of about 360.

The first Small White seen in 2019 was on the 27th February. A good five or six weeks earlier than we would normally expect. The rest of the season was much as expected with a summer population about five times as great as the spring population.

Red Admiral, Vanessa atalanta

The first Red Admiral record of 2019 was on 27th February. This was most likely an individual that had survived the mild winter. There were a few more records in March and April, but it was the first week of June when they started to arrive on our coasts, about three days ahead of the first wave of Painted Ladies. There was another spike in numbers at the end of August, which could have been the next generation. Red Admirals continued to be seen in good numbers until the end of October.

Orange Tip, Anthocharis cardamines

Orange Tips did very well again in 2019. This was probably a result of the great year they had in 2018. They were fortunate that their flight period was before the heavy showers started, so the weather was kind to them.

The first Orange Tip of 2019 was seen on 31st March, about a week earlier than normal.

Green-veined White, Pieris napi

The first Green-veined White was also seen on 31st March. The spring population was a lot larger than average, with the summer generation just being a little more than normal.

Large White, Pieris brassicae

The Large White has never been as numerous as the Small White or Green-veined White. 2019 was a fairly average year for them, which is a little surprising considering how well they did in 2018. The first record was on 11th April and they were recorded through to the 28th September.

I'll continue with the rest of the butterflies seen in 2019 in my next post.