Moth plant Araujia sericifera, an exotic smothering vine in New Zealand: Surveys for candidate biocontrol agents in South America, agent prioritization and safety testing

Abstract

Surveys in the native range of moth plant Araujia sericifera revealed a rich natural enemy biota attacking the plant, including damaging primary pathogens and root-boring and seed-feeding arthropod guilds, contrasting with surveys in New Zealand (NZ) that found only generalist defoliating and sucking arthropod herbivores and two mildly pathogenic fungi. A chrysomelid beetle with root boring larvae Freudeita cupripennis, a fruit fly Anastrepha nigrotaenia, and a defoliating rust fungus Puccinia araujiae were prioritised as potential biocontrol agents. Host-range testing indicated that all three species are sufficiently host-specific to be released in NZ. Approval was obtained to release an Argentinian population of P. araujiae and F. cupripennis, collected in Uruguay. Importation of P. araujiae into NZ was deferred until issues associated with the implementation of the Convention on Biological Diversity and associated development of Access and Benefit Sharing legislation in Argentina were overcome. It is hoped that this will proceed soon. Freudeita cupripennis was first released in 2019 and is established in NZ. An application to release A. nigrotaenia sourced from Uruguay was submitted in 2023. However, several other Anastrepha species are pests of fruit crops and some of NZ’s major fresh produce trading partners require declarations stating Anastrepha spp. are absent from NZ produce. This has delayed approval for the release of A. nigrotaenia as exporters will no longer be able to declare that the genus Anastrepha is absent from NZ if A. nigrotaenia is released to control moth plant. Consequently, trade agreements will require amendments to accommodate this.