Raising Reds

Third time lucky for this kahukura / red admiral

May 2025

I mentioned in the last post that we've had some bad weather in Auckland this autumn. The rain has come in heavy torrents, causing localised flooding and pulverising the autumn flower seedlings I hadn't protected properly. It also meant that the third generation of red admiral caterpillars I have been raising got the full force of the weather.

The Moths and Butterflies of New Zealand Trust (MBNZT) has a current project to re-introduce endemic red admiral butterflies to Auckland. This is not the first local project to do this, as Eden Garden and volunteers in the area have been raising reds for many years, introducing nettles into local reserves to keep the population going. However, its been a drop in the ocean and MBNZT has taken up the challenge.

At the old house I used to have my caterpillar castles (which are not castles in any way, shape or form but a cuboid of insect netting with a zip access door. Not a drawbridge in sight) on tables on the back deck which had a clear plastic roof over it, but was not enclosed. It was a good place to raise the caterpillars so they had a feel for the weather, whilst giving them some protection from the elements. Here at the new house there is no outdoor covered area, much to my laundry's consternation. We enquired about putting some cover over the deck with the washing line, but after we had a quote for the better part of $30,000 to do it, we put a line up in the garage instead. Whilst there is now a wet weather alternative for the washing, there isn't an undercover space for the caterpillar castles.

Caterpillar castles set up for the third generation of red admirals

I have tried raising three generations of reds this season and none of them has gone well. I picked up the first caterpillars not long after we moved and I had put the caterpillar castles on tables in the courtyard adjacent to the house where I thought they'd be protected. Wrong. The westerly wind travels straight up the valley and hits the house despite the neighbouring properties. The caterpillar castles were blown off the tables and some of the chrysalis were damaged.

The second generation I attempted to raise, the castles now on the ground and weighed with rocks, didn't fair better. Some eclosed, but the majority of the were infested by parasitic wasps and died.

I was determined this third generation was going to do better. Couldn't do worse, right?! The castles were moved next to the back door, I patched up any tiny holes I could see and crossed my fingers.

Unfortunately, the nettle pots I have been putting in with the caterpillars are stored outside, because my plant cage is full of plants for the garden. This means I managed to shut predator and competing species in with all generations of the caterpillars and I'm sure the evil South African praying mantis have taken a few caterpillars along the way. This is the chap I managed to shut in with the third generation:

Being outside, the trays I have always used to keep the castles clean fill with water as the rain falls. I'm afraid that a number of the tiny red admiral caterpillars were washed off the nettles in the torrential thunderstorms and drowned in the newly formed pond below them, or flung by the water into the hard ground beyond.

With all these disasters you can imagine my joy when the one chrysalis, formed before the weather raged over New Zealand, eclosed today. Just look at the sun shining through its wings. It is truly a thing of beauty.