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.

Large White, Pieris brassicae

Towards the end of last summer I was pleased to find some Large White, Pieris brassicae, caterpillars on some Nasturtiums in our garden. It had been quite a wet year and I had been a little worried because I hadn’t seen any caterpillars up until then. I kept an eye on them and towards the end of September they were still slowly growing.

On 25th September I was concerned to see that it had been frosty and there was actually ice on the leaves next to the caterpillars. I wasn’t sure if they would be able to survive such temperatures, so I put six caterpillars into a mesh cage under the shelter of an overhang in our roof.

Within a few days they had formed chrysalises on the side of the cage where they spent the winter.

This spring I kept an eye on them and between the 2nd and 9th May they all emerged. What I found interesting was that they were all males. 

I also noticed that all of the Large Whites I spotted flying here were males and it wasn’t until the 7th June that I spotted my first female.

However, I needn’t have worried, because this year the Nasturtiums are covered in Large White eggs and caterpillars and I don’t think I have ever seen so many Large Whites flying here!

Small White Chrysalis, Parasitic Wasp

Last year I notice a number of green caterpillars on some Rocket that was growing between the slabs in our patio.

I assumed they were Small White, Pieris rapae, because I had seen adults laying eggs although I couldn't be sure they weren't the caterpillars of Green-veined Whites, Pieris napi.

Later, once I saw the caterpillars were gone, I looked all over the walls of the house for chrysalises, but could only find one Small White chrysalis.

At the beginning of April this year I was sorting out the garden furniture in anticipation of a family visit when I notice a Small White chrysalis on the arm of a garden chair.

Knowing that it wouldn't be safe I carefully removed it and placed it in a jar lined with paper towel inside one of my rearing cages.

About three weeks later I was checking the chrysalises and noticed a number of small insects climbing around on the walls of the cage. I realised that these were parasitic wasps and I found about 15 of them.

When I checked the Small White chrysalis I noticed a neat round hole in it.

I haven't been able to identify the wasps, but I am interested to know more about their life-cycle. I presume that they either lay their eggs into caterpillars or chrysalises and they must develop inside the chrysalis early in the spring. It was the 24th April when I found the wasps, a time of year when the Small White would be either still be chrysalises or would have emerged into adults. Any eggs the butterflies lay would only hatch in early June, about six weeks ahead. I wonder if there is another host that the wasp uses at that time of year.

Happily there have been a lot of Small White butterflies flying around this year, so a good number made it through without being parasitised.

Butterfly Bonanza

On Tuesday I went for a walk up to the wee valley above our house to look for butterflies. The last couple of weeks had been a little rainy and cloudy and there always seemed to be wind blowing from one direction or the other. However, on Tuesday it was beautifully sunny, 18 degrees with a slight southerly breeze.

Not far from the gate out of the woodland is a clump of Thyme, which is always popular with butterflies. When I arrived there were two Small Skippers, a Ringlet and a Northern Brown Argus on it.

Almost every Marsh Thistle flower had one or more Small Skipper on them.

If not they would likely be occupied by Ringlets.

In the short walk, of about 500 metres up the valley I counted 373 Ringlets and 199 Small Skippers. This clump of thistles had four Small Skippers, a Meadow Brown and it wasn't until I looked at the picture once I was back home that I noticed a Northern Brown Argus on the flower on the left.

There were two lovely fresh-looking Common Blues.

I counted 23 Small Heaths and 71 Meadow Browns.

There were at least 22 Dark Green Fritillaries around, although they were flying backwards and forwards, so there could have been more. I struggled to get a picture of one without another butterfly photo bombing my shot. The pictures below were all taken within 14 seconds. First a Meadow Brown tried to get in on the act.

Then a Small Skipper joined in.

And then a different Small Skipper landed just below it!

This female Dark Green Fritillary was accompanied by two Small Skippers.

This male seemed to have more extensive dark markings than normal.

I saw a total of seven Northern Brown Argus. They were all quite worn-looking, having been out a couple of weeks earlier than normal.

It was amazing seeing so many butterflies in this special valley. I have been visiting it for about 20 years and I have been watching it slowly evolve since grazing has stopped and trees have been planted. Some species, such as the Northern Brown Argus have not been so numerous in recent years, most likely because their larval food plant, Rockrose, is becoming a bit swamped by other vegetation. But other species, such as the Small Pearl-bordered Fritillary and Small Skipper have increased considerably.

Just as I was leaving I thought I should check out the clump of Thyme again and this time there were six Ringlets and a Small Skipper!

Costa Rica Butterflies November 2024 - Part 8

Because of the repairs to the damaged runway caused by flooding our return flight was delayed by 24 hours. We were actually very lucky, as some other guests had been delayed by six days. I remember them complaining to me that they wouldn’t mind six extra days in Costa Rica if it was decent weather, but they weren’t particularly happy to have six more days of rain!

As it turned out we woke up on our last morning to beautiful blue skies. We had to leave for the airport at midday, but after breakfast we installed ourselves next to one of the swimming pools for the morning.

I was just blown away by the number of butterflies that were flying around the hotel grounds that morning. There were continuously about three or four in vision at any one time. Many of them I was now able to identify as they flew past, but there were quite a few unfamiliar ones, too. Better still, possibly because they had limited opportunities to fly or feed the previous few days, many of them stopped off at plants to feed, or even lay eggs.

Despite really feeling that I should spend the last morning of our holiday with my wife, I couldn’t resist chasing after the odd butterfly with my camera! This White-angled Sulphur, Anteos clorinde, was so absorbed with feeding on this Ixora hedge that it allowed me to get close enough to photograph it. Previously I had only seen them feeding high up in Mimosa trees.

It even opened its wings slightly allowing me to see the yellow mark on its upper wing.

It was joined by another white butterfly – a Giant White, Ganyra josephina, which I hadn’t seen previously.

The Ixora hedge was proving to be a real magnet with various skippers (mentioned in my previous post) and other butterflies feeding from it.

A third white butterfly settled on a nearby plant, allowing me to identify it as a Florida White, Appias drusilla. This confirmed my suspicion that I had seen these along the track through the woods.

A little later a tiny yellow butterfly flew past. I was soon in hot pursuit and luckily it stopped to lay some eggs on a weed in a shady spot. I managed to identify it as a Mimosa Yellow, Pyrisitia nise. I had seen similar little yellow butterflies flying through the grounds earlier in our holiday, but they had never stopped, so this was a bonus for me on our last day!

But to top it off I saw a dark swallowtail flying backwards and forwards over an Orange Jasmine shrub by the pool. As I watched it buried into the hedge and started laying eggs. It turned out to be a Ruby-patched Swallowtail, Heraclides isidorus. Such an exciting butterfly to see as my last species of the trip. I later learned that unusually for swallowtails, they lay their eggs in batches, rather than singly.

Eventually we had to tear ourselves away from the pool and get ready to leave the hotel. The journey to the airport was our only real opportunity to see more of the country. I just couldn’t believe the number of butterflies of all shapes, sizes and colours in the verges and surrounding countryside. I felt a mix of delight at seeing them, but tinged with sadness, as I really would have loved to have stopped all the way along the journey to take closer looks!

Of course Costa Rica had the last laugh. While we were waiting for our plane to arrive at the airport I noticed that it was getting darker. Eventually the plane arrived in a tremendous thunder storm that was still going as we took off. I had expected the flight to be delayed while the storm passed, but that wasn’t the case. I have to admit that I was very relieved once we were off the ground and above the storm and it was interesting looking down on the lightening below!

This was meant to be a one-off, holiday of a lifetime. Despite the tropical storm for virtually the whole time we were there, it was an amazing experience. I have never been anywhere where there is so much wildlife, which doesn’t seem to have any fear of humans. And of particular interest to me were the butterflies and I have certainly never been anywhere where I have seen so many. It took me a while after I got home to identify them all, but I managed to identify 68 different species. I can only imagine how many more species I could have seen if the weather had been good and if we had managed to travel to other parts of the country. Now I feel I have unfinished business!

I will definitely have to go back!!