Admiral Butterflies

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.

Admiral pupa

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.



Magpie Moth

During our first lockdown I entertained myself by looking for invertebrate animals in my garden. Photographing them proved to be tricky as many were far too small or way too nimble. Identifying the large, slow ones would have been impossible without the help of iNaturalist NZ   

So far I have identified 70 different species. Disappointingly, only 19 are native or endemic species. 

One of the first insects I noticed was the magpie moth (Nyctemera annulate), probably because it is quite large and flies about during the daytime.  It was first described in 1832 by a Frenchman, Jean Baptiste Boisduval who never came to New Zealand.  Nyctemera means night and day, probably from the black and white colour of the moths while annulate refers to the rings on their bodies. The Maori names are mokarakara (moth) and Tuahuru, tupeke (caterpillar)

You can tell a male from a female moth as the dude has the more feathery antennae.

They’re endemic to New Zealand and are found all over the country wherever there are plants belonging to the Senecio family. I’m not much of a plant person but apparently we have 19 native and 14 exotic species. One of the exotic species, groundsel is a common weed in my garden, hence the magpie moths.  I’m on the lookout for any native species that I could grow instead.  Senecio species contain pyrrolizidine alkaloids which are toxic to humans and livestock. The caterpillars eat them quite happily but it gives them and their moth body a bitter taste making them yucky or possibly poisonous to lizards and most birds. They don’t hide like most tasty caterpillars do but flaunt themselves with their red stripes which may act as a warning. Unfortunately for the caterpillars, the shining cuckoo is unaffected by the toxin and eats them in droves.  There’s always a downside to flaunting oneself.

There is a suggestion that the caterpillars are able to freeze themselves to survive cold weather. I haven’t been able to verify this but it is a pretty cool ability which isn’t shared by many animals. In New Zealand the mountain stone weta and some stick insects can do this. Arctic ground squirrels hold the record among mammals as they can super cool their bodies to -2.9 o C.

 

Maori called the pupa tūngoungou ("to nod") as the pupa’s abdomen bends back and forth. Mavis Lessiter described a game where children would hold the pupa between their thumb and finger and Grandparents would ask questions along the line of “Have you been a good girl?” A wiggle up was yes and wiggle down was no. I have yet to find a pupa in my garden so have no idea whether I have been good or not.