Biocontrol introduction
Target pest: Tropaeolum speciosum (Brassicales: Tropaeolaceae), Chilean flame creeper
Agent introduced: Blaptea elguetai (Coleoptera: Chrysomelidae)
Imported:
2022
Import source:
Chile
Import notes:
Landcare Research (2023b) - sixty-five Blaptea elguetai adults collected from the field in Chile over several weeks, along with 450 eggs laid by those adults, were brought to Christchurch, New Zealand by Landcare Research’s Chilean collaborator in early-November 2022. The beetles continued to lay eggs throughout spring and summer, providing an excellent supply of larvae for host range testing.
Impacts on non-targets:
Landcare Research (2023b) - initial no-choice host range tests were carried out in containment in New Zealand during spring and summer 2022-23. Potential host plants tested included seven species of Tropaeolum [family Tropaeolaceae] (five climbing ornamentals and two species of nasturtium) and plants in closely related families, including the tropical species papaya [Carica papaya, family Caricaceae] and moringa [Moringa sp., family Moringaceae], and five indigenous and five commercially grown species in the family Brassicaceae. All Tropaeolum species were acceptable hosts, although the climbing species all produce foliage in winter, when Chilean flame creeper (Tropaeolum speciosum) and B. elguetai are dormant and no B. elguetai were found on these potential hosts in the wild in Chile. Of the plants tested from other families, one individual B. elguetai managed to develop to the adult stage on each of moringa, Chinese cabbage and pak choi [the latter two both subspecies of Brassica rapa: B. r. subsp. pekinensis and B. r. subsp. chinensis, respectively]. Data analysis calculated the risk of moringa or Chinese cabbage becoming field hosts at less than 5%. The risk for pak choi was higher at 24%, warranting further investigation into this species next spring. However, the results overall suggest B. elguetai is sufficiently host specific for release in New Zealand.
Groenteman et al. (2024) - following analysis of the first set of host range tests [see Landcare Research (2023b) above in this section, and also reported in this publication], further testing of Brassica chinensis, (pak choi ‘Dark Dragon’) [=Brassica rapa subsp. chinensis] was undertaken in August-September 2023. Initial testing had indicated that this species may be at risk of experiencing spill-over attack. However, in these additional trials, no B. elguetai larvae survived beyond second instar on any B. chinensis replicate, confirming that B. chinensis is highly unlikely to be a field host of B. elguetai. In addition, literature searches, conversations with entomologists and growers in Chile, and field surveys of Brassica crops in Chile during the spring and summer of 2023-24 (October 2023 to January 2024) indicate no association of B. elguetai and Brassica crops in the field. It is concluded that B. elguetai is unable to form populations on plants outside the genus Tropaeolum and that even minor spill-over attack on hosts outside this genus is highly unlikely. There are no indigenous Tropaeolum species in New Zealand. However, two other species have naturalised in addition to T. speciosum: T. pentaphyllum (ladies’ legs) and T. majus (garden nasturtium). In New Zealand, seeds of nasturtiums, T. majus and T. minus, are still sold and there are occasional reports of other Tropaeolum species grown in private New Zealand gardens.
Environment Southland (2025) - given the significant economic role of Brassica rapa cultivars in the New Zealand, further testing on selected B. rapa cultivars was undertaken, starting in December 2024, supplementary to testing described in Groenteman et al. (2024) [and Landcare Research (2023b); see entries above in this section]. Blaptea elguetai larvae exhibited a strong preference for T. speciosum when given a choice between potential host plants, with no feeding occurring on the test hosts. While the adults were able to feed and survive to some extent when confined on all four Brassica test species, eggs were only laid on three of them (Chinese cabbage, pak choi ‘Dark Dragon’ and pak choi ‘Hon Tsai’, but not turnip), and egg laying was significantly delayed and at very low levels, and only occurred on 4 out of the 24 test host replicates. In addition, survival and development of offspring from eggs laid during the test were only supported by T. speciosum. The supplementary testing confirms that Brassica species would not become field hosts for B. elguetai and that the beetle is sufficiently host specific for release in the New Zealand environment.
EPA Applications:
EPA (2026) - 28 Jul 2025: application to EPA to import and release the Chilean flame creeper leaf beetle, Blaptea elguetai, as a biological control agent for Chilean flame creeper (Tropaeolum speciosum). EPA Application #APP204815, approved without controls 20 Feb 2026.
References
EPA (2026). Application to EPA (APP204815) to import and release the Chilean flame creeper leaf beetle, Blaptea elguetai, as a biological control agent for Chilean flame creeper (Tropaeolum speciosum). Environmental Protection Authority website https://www.epa.govt.nz/database-search/hsno-application-register/view/APP204815/
Environment Southland (2025b). Application to EPA (APP204815) to import and release the Chilean flame creeper leaf beetle, Blaptea elguetai, as a biological control agent for Chilean flame creeper (Tropaeolum speciosum), Appendix Z: Supplementary host range testing with the Chilean flame creeper beetle (Blaptea elguetai), a biocontrol agent for Chilean flame creeper (Tropaeolum speciosum). Environmental Protection Authority Website https://www.epa.govt.nz/database-search/hsno-application-register/view/APP204815/
Groenteman R, Fowler S, Paynter Q, White R (2024). Host range testing for Chilean flame creeper beetle Blaptea elguetai. Manaaki Whenua – Landcare Research Contract Report: LC4456. 34 p. https://www.landcareresearch.co.nz/assets/Host-range-testing-for-Chilean-flame-creeper-beetle-Blaptea-elguetai.pdf
Landcare Research (2023b). Chilean flame creeper beetle living up to its promise. Weed Biocontrol: What's New? 104, May 2023 https://www.landcareresearch.co.nz/publications/weed-biocontrol/weed-biocontrol-articles/cfc-beetle-living-up-to-its-promise/
