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.

Scottish Borders garden butterflies 2024

We are lucky enough to live in 17 acres of woodland which we have been managing to improve for butterflies and other wildlife. I am developing a wild flower meadow, planted an area of native broadleaves that produce flowers and berries, put in hedges, taken out loads of invasive Rhododendron and planted up various areas with Rockrose and other wild flowers. Our triangle of land is quite a wildlife haven, which in itself causes more challenges. Everything needs to eat, either other creatures or precious plants that I have been nurturing!

It has generally been accepted that 2024 was a lousy year for butterflies in the UK. The Big Butterfly Count confirmed low numbers for most species with record-breaking reductions from 2023 for many species. I have yet to receive all of the record for East Lothian, but my own experience at home here in the Scottish Borders concurs with the national picture.

Although this is only the fifth year that we have been living here I had noticed a pattern developing and numbers of butterflies had been increasing year on year. I can't be sure why that was, but I would like to think it was partially because of the work I have done to manage the habitats here.

In previous years the first butterfly to appear has been the Small Tortoiseshell, which would venture out on a mild spring day to feed on whatever it could find flowering that early in the year. This year, however, I didn’t see any until August and I only saw a total of four all year. I didn’t find any caterpillars either this year, which is unusual. Often I find big clusters of caterpillars on nettles.

Peacocks and Commas are the other two butterflies that over-winter here. At least they both made an appearance this spring, but in surprisingly low numbers. This was particularly disappointing for Commas after I had such a bumper year for them last year. Towards the end of last summer I had been finding caterpillars and chrysalises everywhere, so I expected them to do well. However, this year I only recorded 26 compared to 122 last year.

Despite a poor spring showing the later summer generation of Peacocks did a lot better. The number I saw was only a little lower than average, which is encouraging. Again, I didn’t find any caterpillars, which is unusual.

Orange Tips had a fantastic year here. I recorded 101 of them this year, which is way up on the previous best number of 62. I also saw an unusually high proportion of female Orange Tips.

Despite finding so many caterpillars and chrysalises last year, the number of Small Whites this spring was lower than expected. I did see them throughout the year, though, and ended up seeing 26. This seems a low number compared with the 90s I have seen in previous years, but their numbers do seem to fluctuate considerably from year to year.

I saw seven Large Whites this year, which is about average for this species.

Although I had the impression that there were not many Green-veined Whites around this year, my records show that numbers were only slightly down on previous years. They were more numerous in the spring and the summer generation wasn't so good.

Red Admirals had the worst year by far here. I only recorded 38 in total compared to last year's 474!

Ringlets were here in about average numbers. Not as good as the previous two years, but better than the numbers I had seen before then. There is more suitable ground for them now that we have taken down a large area of Spruce woodland, which has now grassed over and thinned out the trees elsewhere. With the additional habitat it is a bit disappointing that the numbers weren't higher. Certainly higher up the valley where I often walk numbers were well down on previous years.

Last year was really good here for Meadow Browns. This year their numbers dropped back to what I had previously seen here. This was disappointing, as I had thought that Meadow Browns  were appreciating the new areas of grassland. However, numbers up the valley were also considerably down on previous years.

The first Speckled Wood I saw here this year was on 2nd July. Having seen them for the first time here last year I was delighted to see them return, although I had been hoping to see some in the spring indicating that they had bred here. I continued to see them for the rest of the year and ended up seeing 18 - 4 more than last year!

Small Skippers had the worst year since I first saw them here in 2021. They had been increasing in numbers since then, so it was disappointing that I only saw seven here this year. Similarly, in the valley above the house the numbers were lower than normal.

I often chance across a butterfly and think to myself if I had been there five minutes before, or five minutes after I would have missed it. I suppose, though, that there will be hundreds of butterflies I miss because I am not in the right place at the right time. So, this year's lucky spots included one Large Skipper in my meadow. I don't know why I only saw one, as there were a lot in the valley above our house.

As I do most years, I just saw one Small Heath in our meadow. It isn't best suited for these butterflies, so it is odd that most years I see one, just one!!

This year, again, I was delighted to see a Scotch Argus. I just happened to go out to check the Buddleia on a sunny afternoon and spotted a small, dark butterfly. I am still intrigued why I have seen one five out of the last six years here. I am sure there must be a colony close by, which I am yet to find.

Last year I saw my first Wall Brown here in the meadow. This year, I was sitting having lunch outside when a Wall Brown landed on some Marjoram in our patio. They have been slowly working their way in this direction over the last few years.

Disappointingly I only saw one Small Copper here this year. I don't understand why I don't see more as there are plenty of sorrel and dockens growing here for their caterpillars to feed on.

Sadly I didn't see any Northern Brown Argus, Dark Green Fritillaries, Small Pearl-bordered Fritillaries, or Painted Ladies here this year. I saw the first three species in the valley above the house, but in much smaller numbers than normal. This is the second year in a row that I haven't seen a Painted Lady anywhere in the UK!

It is difficult to know exactly why butterfly numbers were so low this year. I am sure it is a combination of factors. There has been much in the news recently about herbicides and loss of habitat impacting on insect populations. I am sure this is true, but I can't see that would explain this year's sudden reduction in butterfly numbers. Last year was really dry throughout spring and summer and I am sure this must have resulted in a reduction of food plants for caterpillars. I noticed how the wild flowers I had planted struggled. Then from September last year more or less until September this year we had so much rain. A damp winter and then limited sunshine later in the year must have had an impact.

It will be really interesting to see what next year brings. I really hope that butterfly numbers bounce back

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!