Butterflies go West
Hugh explains how the white admiral caterpillars are going to be released
In February, Paroa School and Greymouth High School were lucky enough to have a visit from our very own Hugh Gourlay and Murray Dawson, and independent educator Robinne Weiss. The trip was made possible by the Guardians of Paroa Taramakau Coastal Area Trust, who are undertaking important restoration work in Westland. Since Japanese honeysuckle (Lonicera japonica) is a key weed threatening their work, the Trust applied for, and secured, Curious Minds funding to allow the Honshu white admiral butterfly (Limenitis glorifica) to be released there. Although the butterflies, which are native to Japan, have been released elsewhere around New Zealand, these were the first releases in the Westland area.
“When Fran Cohen from the Trust contacted us, she suggested that we release the white admiral on Japanese honeysuckle growing in the area in conjunction with a local primary and a high school,” said Hugh. This was a great opportunity for the students to put into action some of the things they had been learning about. It also extended the reach of another Curious Minds project called The Great Weeds Hunt Aotearoa, which has been raising awareness about weeds and how to identify them with school-aged children in Auckland and Canterbury.
“Working with schools and local communities to release new biocontrol agents provides an opportunity to expose people to the science behind biocontrol and fosters local ownership and monitoring of the releases,” said Hugh. “As well as participating actively in the first regional releases of this Japanese honeysuckle biocontrol agent, the students were also able to engage directly with environmental scientists from Manaaki Whenua – Landcare Research,” said Fran.
“The Trust and Paroa School have been actively working to restore biodiversity near the school and it was great to be able to raise students’ awareness of invasive weeds and involve them in natural weed control methods,” said Murray. Day one began with a visit to Paroa School, where Robinne led the students through some weedy puzzles and activities, before Hugh spoke about biocontrol and passed around a container of the spectacular butterflies. Then in the afternoon more than 1,000 white admiral caterpillars were released by the students onto Japanese honeysuckle growing just over the fence from the school playground. This was followed by the students learning how to use the iNaturalist app to document plants growing in and around the school grounds. About 50 plant species were detected around the school grounds, with two invasive plants, tree privet (Ligustrum lucidum) and arrow bamboo (Pseudosasa japonica), also found nearby. A wide variety of other weeds were also reported, which included the usual culprits, gorse (Ulex europaeus) and blackberry (Rubus fruticosus complex).
The following day Hugh guided Greymouth High School Year 12 biology students through PowerPoint presentations the science behind biocontrol, the methods of finding and collecting suitable agents from their native ranges, rearing them in containment, and host-range testing. He also emphasised the economic benefits of biocontrol programmes. The Trust also did a presentation about their organisation, weed-busting, and options for control. “It is the first time our Trust has worked with Greymouth High School students, and we are thrilled to have gained the funding to make this project possible,” said Fran. Then it was time for these older students to release their caterpillars at a site not far away from Paroa School, and to learn about the local weeds and native plants.
Provided the conditions prove to be suitable, it is hoped that the butterflies will establish and eventually reduce the incidence of Japanese honeysuckle in Westland to the benefit of native vegetation in restoration plantings and more widely. The students will be able to observe when the next generation of adult butterflies emerge, and to monitor the damage of successive generations of caterpillars, as well as, over time, the recovery of the native vegetation.
During the visit Hugh also took the opportunity to speak to the local Rotary group about his work with collecting and rearing biocontrol agents, both overseas and in New Zealand.
Curious Minds Funding is made available by the Ministry of Business, Innovation and Employment to help New Zealanders to be more connected with science. For more about the projects described above, see: https://www.landcareresearch.co.nz/information-for/citizen-science/weeds/about.
CONTACT
Murray Dawson – dawsonm@landcareresearch.co.nz