Have you ever studied a monarch chrysalis up close and noticed its exquisite gold spots? My fascination with monarchs began almost three years ago when a neighbour brought us one on a swan plant cutting for my young son to observe.

Our native monarch butterfly is sadly in decline.

"It's the wasps,” I was told. Monarchs have predators at all stages of their life, but after the accidental introduction of five species of social wasps since the 1940s (German, common and three types of paper wasps), their numbers have been decimated.

New Zealand has some of the highest numbers of wasps in the world. It is overrun by them.

They can attack a bush full of monarch caterpillars in a few minutes, carrying the harmless creatures back to their nest for their young to feed on. The paper wasps are particularly prolific in urban areas, but as they only eat live insects will not feed on poisonous bait so they are harder to control.

I, along with a friend felt compelled to intervene, successfully raising over 100 butterflies indoors on potted swan plants and cutting since January, where they have been safe from all predators, while we enjoyed observing this fascinating insect's development.

Butterflies will visit your garden to feed if you grow nectar producing flowers. So, to continue seeing these marvellous insects in town and not only at Te Puna Quarry butterfly sanctuary, which has a great set up with outdoor as well as indoor swan plants plus nectar producing flowers, I recommend those interested to please:

• plant a swan plant (they will self-seed and you can then keep as many plants as you want)
• ideally raise a few caterpillars indoors where their safety is guaranteed
• kill these alien wasps on your property and destroy or spray their nests at night or early morning when the wasps are in the nest
• plant nectar producing flowers for the butterflies

We have a responsibility to preserve this important plant pollinator and allow future generations to enjoy it too!

Ruth Kenyon-Slade, Otumoetai (abridged).