Biocontrol introduction
Target pest: Araujia hortorum (Gentianales: Apocynaceae) = Araujia sericifera?, moth plant
Agent introduced: Anastrepha nigrotaenia (Diptera: Tephritidae) = Anastrepha australis, Toxotrypana australis
Imported:
2020
Import source:
Uruguay
Import notes:
Landcare Research (2020j) - Anastrepha nigrotaenia [as Anastrepha australis - see taxonomic note (23 April 2023) and Norrbom et al. (2025) entries in ‘General comments’ section] has been collected in Uruguay a number of times between 2010 and 2018, but laboratory rearing was initially unsuccessful due to limited numbers imported into New Zealand and asynchronous adult emergence in containment, and possibly poor host plant quality. A collecting trip from late-January to early-February this year [2020] resulted in over 80 pupae being imported into containment. So far, rearing of the new colony has been successful.
Waikato Regional Council (2023) - Anastrepha nigrotaenia [as Anastrepha australis - see taxonomic note (23 April 2023) and Norrbom et al. (2025) entries in ‘General comments’ section] larvae were collected from developing A. hortorum pods collected in the Punta de Rieles neighbourhood of Montevideo, Uruguay, in January 2020 and imported into containment in New Zealand in February 2020 [see Landcare Research (2020j) entry above in this section]. Host range experiments were conducted from 2020 to 2021 on the colony resulting from this importation. If A. nigrotaenia is released in New Zealand, all individuals released will be progeny of this founding population.
Paynter et al. (2025) - an application to release A. nigrotaenia [called A. australis in the application] sourced from Uruguay was submitted in 2023 [see EPA (2023) entry in 'EPA applications' section below]. During the subsequent consultation period the New Zealand Ministry for Primary Industries (MPI) lodged an objection to the application due to some of New Zealand’s major fresh produce trading partners requiring declarations for the absence of Anastrepha spp. (some of which are major pests of fruit crops) from New Zealand, delaying the approval for the release of A. nigrotaenia. Consequently, although A. nigrotaenia poses no threat to commercial crops, the wording on these trade agreements requires amendment before this species can be released in New Zealand.
Impacts on non-targets:
Landcare Research (2020j) - so far host range tests have been conducted on swan plant (Gomphocarpus fruiticosus), on which females showed no interest in oviposition. Further host plant testing will be done this summer [2020-21].
Waikato Regional Council (2023), Paynter et al. (2025) - Araujia hortorum (family Apocynaceae, subfamily Asclepiadoideae) is the only representative of the genus Araujia in New Zealand. [See Paynter et al. (2025) entry in 'General comments' section below regarding the taxonomic nomenclature of moth plant.] There are only three native species in the same family, all in the genus Parsonsia (subfamily Apocynoideae). No-choice host range tests were conducted on eight plant species representing four tribes and two subfamilies of the Apocynaceae: two native Parsonsia species and six ornamental plant species (including A. hortorum). Development to pupae occurred in approximately 60% of replicates of A. hortorum and 40% of replicates of Oxypetalum coeruleum (tweedia, a minor ornamental plant) (both in the subtribe Oxypetalinae). No pupal development or any signs of oviposition or damage occurred on any of the other test plant species. It is highly likely that A. australis [renamed A. nigrotaenia in 2025 - see Norrbom et al. (2025) entry in ‘General comments’ section] is host specific in the subtribe Oxypetalinae. In fact, laboratory host range testing can overestimate the field host range, and A. australis (and A. nigra and A. proseni, which are now considered conspecific with A. australis [and all synonyms of the more recently published name Anastrepha nigrotaenia - see taxonomic note (23 April 2023) and Norrbom et al. (2025) entries in ‘General comments’ section]) have only ever been recorded from plant species in the genus Araujia in the fruit flies' native range, even though O. coeruleum occurs within that range. Nevertheless, the possibility of non-target attack on O. coeruleum in New Zealand cannot be ruled out. However, if it occurs, damage to pods is likely to be inconspicuous and will not affect the ornamental properties of the plant. The risk of significant damage to native plants in New Zealand is negligible.
General comments:
Taxonomic note (19 April 2023) - the following information is from Waikato Regional Council (2023). Seven species of fruit fly recognised as the ‘curvicauda species group’ were previously included in the genus Toxotrypana, including T. australis (currently Anastrepha australis). Molecular studies reported in 2017 resulted in Toxotrypana being synonymised with Anastrepha. Although Toxotrypana is the senior name, Anastrepha took precedence due to the much greater economic importance of its species. The fruit flies imported into containment in New Zealand in February 2020 showed some variability in colour; however, molecular investigation indicated all individuals were A. australis. Specimens were sent to an overseas expert who found that the external features of flies in culture in New Zealand match the descriptions of three Anastrepha species in the curvicauda group, but molecular work again indicated they were all the same species. That expert also considered it likely that all the species that Blanchard described under Toxotrypana, except littoralis, are colour morphs of the same species, and noted that Anastrepha nigrotaenia (Enderlein) appears to be the valid name for this species, although the taxonomy needs to be revised. Therefore, while the name A. australis will be used for now for the New Zealand material, the name is likely to change to A. nigrotaenia once a taxonomic revision has been completed and formally accepted [see Norrbom et al. (2025) entry below in this section].
Norrbom et al. (2025) - flies of the curvicauda group of the genus Anastrepha with different colour patterns that were previously recognised as four species are reported to be colour morphs of a single species, Anastrepha nigrotaenia (Enderlein), new combination, on the basis of morphological and molecular study. The names Toxotrypana australis Blanchard, Toxotrypana nigra Blanchard, Toxotrypana picciola Blanchard, and Toxotrypana proseni Blanchard, as well as Toxotrypana pseudopicciola Blanchard, previously considered a junior synonym of T. nigra, are considered new synonyms of A. nigrotaenia.
Paynter et al. (2025) - most countries with invasive moth plant populations follow Forster and Bruyns (1992), who considered Araujia hortorum Fourn. to be synonymous with A. sericifera. Nevertheless, there are consistent differences between the two taxa, suggesting that A. hortorum and A. sericifera are either two separate species, as was proposed by Meyer (1944), or two sub-specific entities within the same species. In New Zealand, moth plant is currently referred to as A. hortorum although the Landcare Research New Zealand Plants website states that “A. sericifera and A. hortorum are very closely related entities and probably do not deserve recognition at the species level”. Nevertheless, it notes that “specimens from Australia and New Zealand and those conserved in the main herbaria of Argentina and Uruguay clearly belong to the taxon here considered as A. hortorum Fourn.”
EPA Applications:
EPA (2023) - 22 Feb 2023: application by the Waikato Regional Council to import and release a fruit fly, Anastrepha australis, a biocontrol agent for moth plant, Araujia hortorum. EPA Application # APP204305. Status is “submissions closed” [i.e. a decision has not been made regarding the application, as of December 2025] [see Paynter et al. (2025) entry in ‘Import notes’ section above for details regarding the delay of the decision].
References
EPA (2023). Application to EPA (APP204305) to import or release the fruit fly, Anastrepha australis, as a biological control agent for moth plant, Araujia hortorum. Environmental Protection Authority website https://www.epa.govt.nz/database-search/hsno-application-register/view/APP204305/
Landcare Research (2020j). A seed-damaging fly for moth plant? Weed Biocontrol: What's New? 94, Nov 2020. https://www.landcareresearch.co.nz/publications/weed-biocontrol/weed-biocontrol-articles/a-seed-damaging-fly-for-moth-plant
Norrbom AL, Matthew MR, Paynter Q, McGrath Z, Probst CM, Korneyev VA, Wiegmann BM, Cassel B, Rodriguez EJ, Steck GJ, Sutton BD, Branham MA, Ruiz-Arce R (2025). Color morphs in Anastrepha nigrotaenia (Enderlein), new combination (Diptera: Tephritidae) and resultant synonymy. Proceedings of the Entomological Society of Washington 126(1): 21-55 https://doi.org/10.4289/0013-8797.126.1.21
Paynter Q, Anderson FE, Barton J, Bianchinotti MV, Bownes A, Carpintero D, Delgado S, Delhey R, Gourlay AH, Hayes L, Kiehr M, McGrath Z, Ramírez GH, Testoni D, Villamil CB, Villamil SC (2025). Moth plant Araujia sericifera, an exotic smothering vine in New Zealand: Surveys for candidate biocontrol agents in South America, agent prioritization and safety testing. Biological Control, Vol. 210, November 2025, Article No. 105901 https://doi.org/10.1016/j.biocontrol.2025.105901
Waikato Regional Council (2023). Application to EPA (APP204305) to release a new organism, the moth plant fruit fly, Anastrepha australis. Environmental Protection Authority website https://www.epa.govt.nz/assets/FileAPI/hsno-ar/APP204305/APP204305-Application-.pdf
