Mastodawn

@rnzbot_nz This article is referring to a short report on the website of the Moths and Butterflies of NZ Trust (link below). It shows a concerning decline in butterflies since 2009 along a monthly transect through the streets of Nelson walked by Kiran Thodiyll Kanakambujan.

Comparing with iNaturalist observations, the decline is at least consistent with the rise in observations of exotic paper wasps in the area. These are big predators of caterpillars, as the RNZ article notes.

We need a lot more monitoring like this. While the news headline boldly pronounces a significant decline in New Zealand's butterflies, that's not my impression from surveying butterflies in and around Christchurch city. I think it depends a lot on location. Worryingly, European paper wasps are just starting to ramp up in numbers in Christchurch while they've been abundant in Nelson for a decade.

If you want to contribute to standard butterfly monitoring, the Trust recommends butterfly-monitoring.net.

https://www.nzbutterflies.org.nz/wp-content/uploads/Kiran-Brief-Report-Nelson-Transect.pdf

https://butterfly-monitoring.net/

#insects #insectSurvey #entomology #butterflies #nz #EcologicalMonitoring

Jon Sullivan Nov 24, 2025

I spent yesterday at Travis Wetland, Ōruapaeroa, which is a large wetland restoration site in eastern Ōtautahi-Christchurch, NZ. One of my MSc students, Tommy, is embarking on an invertebrate survey of the wetland, and we spent the day setting up Malaise traps (to catching flying insects) and pitfall traps (to catch invertebrates on the ground).

Tommy is repeating a survey done back in 1995–1996, when the wetland (then mostly wet farmland) was being purchased from a housing developer by the City Council.

We expect a lot to have changed (hopefully mostly for the better) as the vegetation of the wetland is much more diverse and native than it was.

Stay tuned over the summer for insect discoveries.

#entomology #wetland #restoration #InsectSurvey #insects #nz #LincolnUniversityNZ #research