Where have all the monarch butterflies gone?

There is real concern for the health of New Zealand's monarch butterflies. 

A survey of 340 Kiwis by the Moths and Butterflies of New Zealand Trust showed three-quarters of people are worried about a decline in the species. 

Half of the respondents said they had seen virtually no eggs, caterpillars or chrysalises in their gardens.

Jacqui Knight, a spokesperson for the Moths and Butterflies Trust, says the decline could be to do with pests.

"Predators like wasps and ants are killing them and the introduced South African praying mantis eat the caterpillars as well," she told Newshub on Wednesday.

She says there are things people can do to protect the species - including planting plants which benefit butterflies and other pollinators such as bees.

"Nectar species are great for bees and other species too," she said.

Knight says the monarch butterflies have a large part to play in New Zealand.

"The monarch butterfly is amazing as it's so big and beautiful in all four stages so it can inspire people and children and adults too to respect all nature."

If monarch butterflies are in decline, Knight says it's a sign of much wider issues.

"The monarch is an indicator species. Their presence tells us our gardens are great for pollination - and the survival of the human race depends on pollination," she said.,

Christchurch ecologist Brian Patrick is equally as concerned.

"Some of our butterflies are teetering on the edge of survival," he said.

"The plight of our butterfly fauna is heavily dependent on human respect if they are to survive and thrive."