Since 2009, a member of the Moths and Butterflies of New Zealand Belief has walked the identical route weekly from October to March, recording butterfly numbers.
That knowledge was used to provide a report, which discovered widespread and paper wasps have been guilty.
“The most definitely drivers are environmental pressures, notably launched pest wasps (Vespula and Polistes spp.).” founding trustee, Jacqui Knight mentioned.
She mentioned a wasp survey completed in 2025 confirmed the pests have been killing native bugs like wētā and younger birds, whereas additionally “limiting individuals’s capability to work and benefit from the open air”.
“We’re involved that different species are in decline as properly, however the monarchs are a lot bigger and used to grace our gardens each summer season – so their absence is way more noticeable.”
Knight is urging the federal government to take the impression of these extra significantly and is asking on volunteers to participate in butterfly transect monitoring.
“There are different elements affecting our native fauna as properly that should be addressed. Our work is simply starting.”
