A team from Manaaki Whenua, Landcare Research in New Zealand, travelled to Rarotonga last month to conduct routine monitoring of biocontrol agents – the red postman butterfly, African tulip tree flea beetle and balloon vine rust. These biocontrols were released in previous years, dating as far back as 2016, to reduce the spread of several invasive species.
NES staff joined the Manaaki Whenua team, Te Ipukarea Society and Ian Karika at the Takitumu Conservation Area to revisit sites where the African tulip tree flea beetle was released. There, they found a considerable amount of damage by the adult beetle to the African tulip tree, indicating that the biocontrol is doing well since its release last year.
During the remaining days, NES accompanied the team in surveying of passionfruit species across the island, looking for signs of damage by the balloon vine rust on the invasive red passionfruit (Passiflora rubra), but also checking for signs of damage on other edible passionfruit species.
Non-native red postman butterflies were also collected at sites in Turangi, Papua and Avatiu. The samples collected are part of an ongoing project by Manaaki Whenua to analyse genetic changes of the species over time.
After collecting 100 specimens of the Red Postman at various sites, these were brought back to base and processed for laboratory work. Post examination results will be sent back to the Cook Islands
