Of Caterpillars and Chrysalises Part 2

Continued from my previous post.

I can’t believe the number of eggs I have found this year of Large Whites, Small Whites and Green-veined Whites. There have been a lot of adults flying around and my Nasturtiums have been covered in eggs. 

The Large White lays its eggs in batches on the underside of the leaves.

The other two species lay their eggs individually anywhere on the plant. They have also been laying eggs on a Rocket plant growing in our patio and on Bittercress and Garlic Mustard.

I tried to photograph some Large White eggs and various stages of their development as caterpillars, but there were so many different batches of eggs I couldn’t keep track of which were which.

There were so many caterpillars that some of the Nasturtiums were completely stripped of leaves. I tried to pick leaves from other plants, but discovered that most of them had new batches of eggs on them. So, I resorted to buying bags of Curly Kale to try to keep the caterpillars alive! I have never seen so many caterpillars!

Once they were ready to form chrysalises they crawled up the wall of the house to find a sheltered spot.

Unfortunately, a few were parasitized by Braconid wasps. Presumably the adults had laid eggs inside the caterpillars at some point and the larvae burst out of the chrysalises to pupate.

And the Bluetits learned where to look for the caterpillars, flying up to the wall and picking off the chrysalises. Even the chrysalises that I had thought were safe were picked off by wasps, biting into the chrysalis and managing to prize them off the wall! I was feeling a bit despondent, seeing so many chrysalises perish after I had put the effort in to save the caterpillars. 

However, I needn't have worried. One day I noticed a Small White butterfly emerging from under the Alpine trough. I had a look underneath the trough and there were several more Small White chrysalises under there.

During the late summer/early autumn there have been loads of Large Whites, Small Whites and Green-veined Whites flying around.

On 12th July I noticed a hutchisonii form of Comma laying eggs on the nettles behind my garage. I wasn’t able to look for the eggs for fear of being stung, but on the 7th August, I was walking past the garage when I spied a little face peeking out from below a nettle leaf. It was a Comma caterpillar.

I watched it for a few days and on the 10th August it formed a chrysalis.

Unfortunately, it is now the end of September and nothing has emerged from the chrysalis, so I fear it may have failed.

I was down in my meadow one day in August, when I noticed a nettle bouncing around. I couldn't understand why it was moving like that on a still day. On closer inspection I noticed that the top leaves were stitched together and on top of the leaves was a parasitic Ichneumonid wasp.

I chased the wasp away and investigated further and found a Red Admiral chrysalis inside the nettle leaves. A little later when I walked back the nettle was bouncing around again and the wasp was back. So I decided to pick the nettle and put it in a mesh cage. I thought that in a few weeks I would either have a Red Admiral or a number of wasps! Luckily it was a Red Admiral that emerged from the chrysalis about three weeks later.

I don't think I have ever known such a good year for finding caterpillars and chrysalises!

Red Admiral, Vanessa atalanta

I am lucky enough to have a large floor-to-ceiling window in my study, which overlooks a weedy area of our woodland. I am often distracted from my work by a butterfly fluttering past and on quite a few occasions I have seen butterflies laying eggs there.

On the 1st July I spied a Red Admiral flitting about from nettle to nettle. I made a mental note of one nettle where it had landed and sure enough, when I looked later there was an egg.

I picked the nettle and popped it in a jar of water. The hole in the lid was only just large enough for the stem to fit through, so that the caterpillar can't fall in! On the 9th July the egg hatched, producing a little black caterpillar. It hung around on the small leaf the egg was laid on for a few days, but the leaf started to dry up, so I cut the leaf and put it onto a fresh nettle.

The caterpillar immediately climbed onto the fresh leaf and tried to stitch the edges of the leaf together. This was rather ambitious for such a small caterpillar. As it grew bigger it did manage to stitch the edges of the leaf together to form a tent. The caterpillar would spend all day inside its tent, only coming out at night to eat or construct a new tent. It was rare to see the caterpillar in the daylight during this time.

By early August it had reached a good size and after a period of frenzied eating I noticed that the caterpillar was hanging upside down inside its tent. On the 7th August I saw that it had formed a chrysalis.

The chrysalises have amazing metallic green marks on them.

On 21st August, I noticed that the chrysalis had darkened slightly, and I thought that the butterfly would be emerging in a couple of days. However, about an hour later I looked round to see a butterfly hanging from the leaf! 

It wasn't a particularly sunny day, but after a few hours the butterfly flew off to a nearby bush, to join the other Red Admirals feeding there.

So, this Red Admiral had been an egg for 9 days, a caterpillar for 29 days and a chrysalis for 14 days. I found another, much lighter, caterpillar in the nettles , which I put into a mesh cage on a nettle stem. A few days later it formed a chrysalis, but this one remained in that state for 21 days. It is interesting how much longer it took to emerge.

As I write this in the middle of September, there are still caterpillars and chrysalises on the nettles outside my window.  The number of butterflies has dropped over recent weeks, but Red Admirals have been really abundant. Last week I counted 67 of them on my Buddleias and I noticed a few days ago they are also feeding on Yew berries.

Red Admirals are usually the last butterflies I see each year, with them sticking around until the end of October. I presume they then fly south, but it always intrigues me that they stay here long after the first frosts.

Red Admiral, Vanessa atalanta

On 22nd June I was working in my study when I notice a butterfly out of the corner of my eye. I am easily distracted that way, so looked round and saw it was a Red Admiral and it was inspecting the nettles right outside my window. I spotted it laying an egg and, as I have mentioned before, my study window looks out on the hen run, so I doubt any caterpillars would last long.

At lunchtime I popped out and picked the nettle that the egg had been laid on. I kept it in a jar of water with a hole punched through the lid. All of these photos were taken with my phone. This one was taken looking through a microscope.

Seven days later the egg hatched, but I couldn't find the caterpillar. After three days I spotted it in the young shoot at the top of the nettle stem. It stayed there for another five days in a sort of web it had made and once it had eaten most of the young leaves it moved to a larger leaf further down the stem, where it started constructing a tent.

I kept putting fresh nettle stems in the jar and I noticed that the caterpillar would spend the day inside its tent. The following morning I would find the tent completely eaten and a new tent formed on the new stem. This happened for a further 19 days during which I didn't see the caterpillar.

On the 25th July no new tent had been formed and I managed to see the caterpillar hanging in a characteristic J-shape inside the leaf tent. The following day it had formed a chrysalis and I was able to open up the tent to get a better look.

It remained as a chrysalis until the 8th August, when it emerged as a butterfly. Over the previous two days the chrysalis darkened and I was able to make out the pattern of the top sides of the wings. A couple of hours before it emerged I could see the abdomen section of the chrysalis lengthen slightly, however, I still managed to miss the actual point of emergence!

So, it was seven days as an egg, 26 days as a caterpillar and 13 days as a chrysalis.

This is an almost identical story to the Red Admiral egg that was laid in the hen run last year. On that occasion the egg hatched after only four days, it also remained as a caterpillar for 26 days and it remained as a chrysalis for 16 days.

Once its wings had dried I took the butterfly outside. It spent a while warming up in the sun, then took off and did a couple of laps of the patio before flying off to join the other Red Admirals on the Buddleia.

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.

Red Admiral - Vanessa atalanta

2017 was generally not a  good year for butterflies here in South East Scotland, but strangely it was a very good year for Red Admirals, Vanessa atalanta.

In previous years the Red Admiral was considered to be a summer visitor to Scotland. They would arrive here from May to July from the continent and would lay eggs to produce the next generation, which it was thought either perished or returned south for the winter. However, over the last few years there have been a number of early sightings of Red Admirals here, suggesting that they are able to survive the milder winters we have had recently. Sadly, the long cold winter we have just had appears to have killed off all of the Red Admirals, but I notice that in southern England enthusiasts have found eggs and caterpillars throughout the winter.

The caterpillars nip the stems of nettles, causing the top to wilt over and then they create a little tent for themselves by stitching the edges of a leaf together.

Last year there were a lot of caterpillar tents seen and I decided to collect a couple to watch the caterpillars' development. I picked two nettles containing caterpillars on 22nd August and put them in a pot of water with other nettles for the caterpillars to feed on. It turned out the caterpillars were very close to forming into chrysalises.

Two days later, on 24th August, I noticed that one had formed a chrysalis on roof of the container. 

The other caterpillar had made its way to the top of the container and woven silk to form netting on the plastic window. The next day this caterpillar was hanging by its tail end from its silk pad.

The following day, the 26th August, the second caterpillar was still hanging by its tail end. I took the cage outside and within 30 minutes saw it was now forming a chrysalis.

It was a further 28 days before a butterfly emerged from the first chrysalis on 20th September. The second chrysalis also took 28 days to eclose, with the butterfly emerging two days later.

Unfortunately, they both emerged while I was at work, so I didn't see the adult butterflies. I was interested that they both chose to form their chrysalises on the roof of the cage. As far as I am aware they normally form the chrysalis within the tent they have made out of nettle leaves. Maybe the shelter of the cage made them feel secure.

East Lothian Butterflies 2017 - Part 1

2017 was a strange year for butterflies. It started off reasonably well, but the summer butterflies were rather disappointing. Luckily there was a late autumn resurgence of Speckled Woods and Red Admirals, which boosted the overall number of butterflies seen.

We had a good spring in 2017 after a mild winter with only one dusting of snow. From the end of March until mid-June we had decent weather, but then we had a period of very heavy rain. This seemed to impact on many species of butterflies (and I am told some species of birds). Certainly I saw a batch of Small Tortoiseshell caterpillars wiped out by the rain in June and also an enormous group of Peacock caterpillars perished after three days of continuous rain in July.

This year, we had more people than ever sending in records. This has given a bit of a false impression of the number of butterflies that there were around. One thing I noticed this year was that there were very few records of large numbers of butterflies being seen.

I have looked back over the last five years' worth of records and noticed a worrying trend in that the number of butterflies per sighting has been steadily reducing each year.

Below is a summary of how each species did in 2017.

Peacock, Aglais io

A really early sighting this year, the first Peacock record I received was on 16th January on an unusually warm and sunny day. They were recorded every month through to November, with numbers peaking towards the end of August. Peacocks did reasonably well this year, unlike the Small Tortoiseshell, which has a very similar life cycle.

Small Tortoiseshell, Aglais urticae

The first Small Tortoiseshell was spotted on 25th January. They had a very poor year this year and despite the record number of butterfly records sent in, we had our lowest number of Small Tortoiseshells recorded for five years. What I found interesting is that the first Small Tortoiseshell recorded hibernating was on 17 August, only a couple of weeks after it must have emerged. More hardy Small Tortoiseshells were seen flying until 14th September.

Red Admiral, Vanessa atalanta

The first Red Admiral recorded was on 9th March. I would speculate that this was an individual that had spent the winter here. They were seen every month after that right through to December, with numbers peaking in September. This was our most commonly recorded butterfly this year, and it did very well all over the UK. This is a butterfly that only a few years ago was considered as a migrant, but which has now firmly established itself here.

Comma, Polygonia c-album

The first record of a Comma this year was on 12th March. The Comma has never been a particularly common butterfly in East Lothian. Since first being recorded here in 2001 their numbers have picked up each year, peaking in 2015. For some reason 2016 was a terrible year for them and in 2017 there have been a few more seen, but still worryingly low numbers.

Green-veined White, Pieris napi

The first Green-veined White was recorded this year on 1st April. They seemed to have a fairly average year, but I think in reality numbers were lower than usual (given that we had more people recording butterflies). Certainly, the number recorded on the transects was lower than average.

Orange Tip, Anthocharis cardamines

The Orange Tip was first recorded on 6th April. The number recorded was a little higher than average, as expected. The adult stage of this butterfly usually flies between April and mid June, so they missed the terrible weather just after that.

Speckled Wood, Pararge aegeria

The first Speckled Wood was seen on 8th April. There are generally three peaks in population of adult Speckled Woods throughout the year. Possibly the first to appear had spent the winter as a chrysalis. The second peak, in June, could be those that spent the winter as caterpillars. This year the number of records received in June was much greater than in previous years, but the later generation was not so spectacular, although there were a great number of records received in late September, making this the second most numerous butterfly recorded in East Lothian in 2017.

Small White, Pieris rapae

The Small White was also first recorded on 8th April. I think that the Small White is generally a little unrecorded, as it is difficult to identify unless it lands. 2017 started off reasonably well for the Small White with normal numbers being seen in the spring. However, the summer generation was very reduced, presumably as a result of the heavy rain during June and July.

Large White, Pieris brassicae

The Large White would normally follow a similar pattern to the Small White. The first record for 2017 was on 8th April and thereafter the Large White had a fairly average year. More were recorded this year than the previous three years, but remember there were more people recording them. Why the Small White struggled and the Large White didn't appear to be affected by the weather is a mystery to me!

Wall Brown, Lasiommata megera

The Wall Brown was one of 2017's success stories. First recorded here in 2010 the Wall Brown has since been spreading westwards around the coast and to several inland sites. In 2017 the first record was on 20th April and the first generation continued to be seen until  3rd June. The second generation started on 5th August and it was recorded through to the 19th September in much greater numbers than in previous years.

Small Copper, Lycaena phlaeas

The Small Copper has been fairly consistent in East Lothian over the last five years. 2017 wasn't very different from the average. 

I will continue with the remaining 12 species in my next post.