There are two species of admiral butterflies in NZ, both of which frequent my garden: the Red Admiral (Vanessa gonerilla ) whose Maori Name Kahukura means red cloak and the Yellow Admiral (Vanessa itea) whose Maori name, Kahukowhai means yellow cloak. The red admiral is endemic to NZ while the yellow admiral is a native also found in Australia. It is thought they blew over here from Australia in recent times, but before Europeans arrived.
The males are territorial and will investigate any other butterfly in the hopes that it might be a lovely female. I’ve occasionally been treated to the sight of a yellow admiral chasing a much larger monarch butterfly over the fence and into the neighbour’s garden. Not sure if it had amorous or aggressive intentions.
The females lay eggs on the stinging nettles in my garden. When hatched, the caterpillars roll up a leaf and join it up with silk to make protective “tent”. They eat this leaf from the safety of inside, then move onto another leaf.
Before pupating, the caterpillar finds a suitable spot, often on the weatherboards of my house and sometimes through an open window and inside. They hang in a “J” position for a day or so and then turn into a pupa. I haven’t managed to be around at the right moment to witness this but always hopeful.
Like a great number of other species, the admiral butterflies are in decline due in part to loss of habitat. You can do your bit here, by leaving a patch of stinging nettles in your garden for them.
A bigger problem is predation by introduced wasps. First is the white-spotted wasp. It arrived from Australia around 1915 and is harmless to you and me. The female injects eggs into pupae of moths and butterflies and is particularly fond of the admirals. I haven’t found any of these wasps in my garden yet. At least I’ll be able to see them unlike the second predator Pteromalus puparum which we foolishly introduced into NZ in the 1930’s to control white butterflies which we imported in 1929 probably on coolstore vegetables.. This tiny, ant sized parasite injects its eggs into the pupa. The eggs hatch and gobble up the caterpillar from the inside. They pupate inside their host and eventually emerge where upon they mate immediately and search for fresh pupae to infect. Charming! Thirdly, the larger introduced German, common and paper wasps will also find caterpillars and take them back to their nests to feed their larvae.
In a Maori legend, the Goddess Hine-nui-te-Po wanted a drop of Maui’s blood so that she could make a spell to enable her to kill him. Firstly she asked Kahukura to help but he was too visible and he was killed. Next she asked the mosquito but he was too noisy and he was killed. Finally she asked the sandfly and he was just right and she obtained her drop of Maui’s blood.