Sunday, 3 January 2016

Puriri Moths and Caterpillars - a secret to discover in the trees

It was a magical moment when I first touched the cover of the puriri caterpillar's hole. A soft membrane, like a skin, covers the hole the caterpillar has made. Inside it's turning into a moth. But to the untrained eye, the membrane looks like a brown mark on the tree trunk.
The membrane over a puriri caterpillar hole

Once the moth has emerged, a hole is left in the tree. These holes become home to other insects, such as weta. One species of tree that the caterpillars like is the putaputaweta tree, so named for the wetas living in the holes. A couple of days ago, I found a mahoe tree, that looked something like a puriri caterpillar motel, it had so many holes all in a row.
A row of puriri caterpillar holes - all empty

Perhaps given the name of the moth, it isn't surprising the one of the trees the caterpillar likes is the puriri tree! But this name is the common English name, a common Maori name is pepe tuna.

A puriri moth found in the bush

The moth is New Zealand's largest, like many moths its mostly active at night and only lives for a few days.

Although its only found in the North Island of New Zealand, I still wanted to include it in my book "In the Bush: explore and discover New Zealand's native forests" because kids and adults find them fascinating. If you live in the South Island, I hope you can find them when you visit the bush in the North Island.
page 12 of "In the Bush"
Searching for these secret holes is an interesting purpose for a bush walk with children.

Places you can find puriri caterpillar holes in trees around Wellington:
Zealandia, Nga Manu Nature Reserve, Butterfly Creek, Kaitoke Scenic Reserve, Porirua Scenic Reserve, Maungakotuktuku Scenic Reserve, Otaki Forks...

To find out more about puriri moths: 
Terrain (Taranaki Educational Resource) is a great site for information about New Zealand natives, plants and animals
Landcare Research have a fact sheet
Nga Manu Nature Reserve has amazingly been able to record the emergence of a puriri moth from its hole