More than 30 monarchs swarmed across Margaret Innes' garden and house. Photo / Bevan Conley
More than 30 monarchs swarmed across Margaret Innes' garden and house. Photo / Bevan Conley
A Whanganui woman is encouraging locals to plant milkweed species in their gardens to help stave off the decline of monarch butterflies.
This comes after Margaret Innes woke up one morning last week to find more than 30 monarchs swarming her garden.
She said she hadn't seen so many monarchs in her garden in more than three decades of living at her Liverpool St house.
Innes has been fascinated by the insects for years, planting milkweed species such as swan plants in her garden to give the monarchs a place to feed and grow.
"They are some special creatures. I've never seen this many here and I've been here for over 30 years.
"They are coming out a bit earlier than usual this year."
Margaret Innes with a freshly hatched monarch butterfly in her garden. Photo / Bevan Conley
Retired butterfly scientist Brian Patrick said the monarch butterfly originated from Mexico and slowly migrated across the globe in the first half of the 1800s.
"It evolved in Mexico. Just like humans, at a certain point in its history, it suddenly went global."
Patrick classes the monarch butterfly as an "assisted native" species because it got here on its own through wind currents, but relies on humans to provide its food source.
"New Zealand is the only place it got to where the female couldn't find a plant or native flora to lays its eggs on. Even little countries like Niue had a representative of the milkweed family where the female could lay its eggs.
"They need humans to feed them and look after them."
He said monarch butterflies were declining because of a variety of introduced wasps; mainly the common, German and paper wasps.
"They are the three big wasps that take the caterpillars. There is anecdotal evidence and observations that there are more wasps around than ever before. In my opinion, that is what is causing the decline."
The butterfly has a lifespan of 60 to 70 days during the summer, but this extends to six or seven months if the butterfly pupates in autumn.
Patrick said people could help the monarchs by trapping wasps and planting more milkweeds.
"Remember they are assisted, we just need to assist them more."
Innes encouraged locals to plant milkweeds such as swan plants to give monarchs a place to eat and grow.
