The earlier pictures were taken on my wee compact Canon ixus 970IS, which involved sneaking up on the butterflies. This can be very frustrating when they fly off, but very rewarding when they don't!

Since 2012 I have been using a Panasonic Lumix FZ150, which allows me to zoom in to the butterflies from a couple of metres away.



Sunday, 26 April 2015

Trials and Tribulations of being a Caterpillar

Many of the plants in our small garden have been specifically planted to provide nectar for bumble bees and butterflies. Others have been planted hoping that butterflies will lay their eggs on them. Last year I planted Nasturtium seeds in any bare areas of the flower beds. These not only provide a nice splash of colour, but the flowers attract bumble bees and various species of white butterflies lay their eggs on the leaves.

I was delighted to find some Small White, Pieris rapae, eggs dotted around the Nasturtiums. They lay their eggs singly.

One day I noticed a Large White, Pieris brassicae, laying eggs on a Nasturtium leaf. They tend to lay their eggs in batches of about 30 or 40 eggs. It took the female butterfly about fifteen minutes to lay this lot on 27th July.

I hoped to keep a diary of the progress of these eggs, but sadly August turned out to be much colder than normal. On 5th August the eggs hatched.

Within a couple of days the caterpillars had chewed a hole in the leaf and they all mad their way to the underside.

There they stayed for several days, not growing at all. This picture was taken on 23rd August.

Then a few days later they were all gone. I watched several batches of eggs and they all went through the same process and sadly the caterpillars all appeared to die. Similarly, the Small White eggs hatched, but the caterpillars didn't grow. I can only assume that the weather was just too cold for them to develop.

Earlier in the year I noticed that a Garlic Mustard plant I had planted in a pot had some Large White caterpillars on it. I had planted this in the hope that a passing Orange Tip, Anthocharis cardamines, would lay an egg on it, but I was happy enough to have these caterpillars instead.

The caterpillars grew quickly, but one day I thought they were behaving a little strangely. They had all climbed to the top of the seed heads. I wondered if they were looking for food, so moved a couple of them onto fresh leaves, but they just crawled back up to the seed heads.

The following day when I returned home from work I was horrified to find that the caterpillars had all been parasitised. The next picture is a little gory. It shows the pupae of a parasitic wasp. The adult must have laid eggs in the caterpillars when they were much smaller and the wasp larvae had been living inside the caterpillars all of the time I had been watching them. They appeared to be quite healthy up until the day before the wasp larvae appeared.


I was concerned that the number of Large White butterflies may be low this year due to the lack of success of the caterpillars that I had seen. Happily I have already seen a couple of Large Whites this year, so hopefully they did better elsewhere.

What perils these caterpillars go though in their short lives. Hopefully they will have more success this year. I will keep my eyes on the plants in the garden and report any good news stories!

5 comments:

  1. These are very interesting images because they show life as it is. I had to witness the tree where I photographed the whole Monarch life cycle being cut down. Apparently a car ran into it, so the whole tree had to be removed. I also saw an invasion of aphids attacking the Monarch larvae once; not a nice sight to see. Thanks for sharing these, I like them, even when it wasn’t the expected outcome.

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    1. Yes, it is all a bit grizzly, but if all of the caterpillars survived we would be overrun with butterflies!!! What a shame about the tree the Monarchs lived on. I hate it when trees are removed because they are considered dangerous. The road out of our village was lined with old Ash trees. Many of them were hollow and housed bats and nesting birds. The landowner had them all sawn down because he was scared they would fall on someone!

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    2. And bats are so beneficial! 😞

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  2. Nick, This is a very sad but caring story. Nature is amazing. Hard to understand sometimes. Such intrigues going on all around us. I love nasturtium too and the flowers are edible and so lovely in salads. I cannot grow it anymore since the rabbits like it too. I hope you see lots of Whites this year and I look forward to your good news stories and your gorgeous photographs.

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    1. Thanks Carol. The weather recently has been cold and rainy. Yesterday was the first day in over a week when butterflies were out and about and I was lucky enough to see quite a few. Unfortunately the rest of the week looks as though we are returning to rain and wind!

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