Biocontrol introduction
Target pest: Ulex europaeus (Fabales: Fabaceae), gorse
Agent introduced: Agonopterix umbellana (Lepidoptera: Depressariidae) = Agonopterix ulicetella, gorse soft shoot moth
Imported:
1982, 1983, 1990, 1996, 2001
Import source:
England (1982, 1983, 1990), UK via Hawai'i (1996, 2001)
Import notes:
Cameron et al. (1989) - three shipments of A. umbellana [as A. ulicetella] were sent from the Commonwealth Institute of Biological Control at Silwood Park, England to New Zealand in 1982-83 for host range testing in quarantine. Cytisus proliferus (tagasaste), a potentially economically important plant in New Zealand, appeared to be a possible alternative host; there are no plans to release A. umbellana in New Zealand until field studies in England show it cannot colonise tagasaste.
Gourlay (2011d) - field trials in Hawai'i (where A. umbellana was released as a biocontrol agent) showed it was safe to release in New Zealand; consequently, it was imported again from England in 1990.
Landcare Research (2007a) - specimens of A. umbellana from Hawai'i, dated 1996 and 2001, are present in the Biological Control Voucher Collection of the New Zealand Arthropod Collection [indicating importations from Hawai'i in those years].
Released:
1991
Release details:
Harman et al. (1996) - Agonopterix umbellana has been released throughout New Zealand since 1990.
Hill et al. (2000) - Agonopterix umbellana was first released in 1991.
Landcare Research (2006c) - efforts to re-release A. umbellana in the North Island, where they are rare, have begun.
Gourlay (2011d) - Agonopterix umbellana was released widely throughout New Zealand in the early-1990s.
Establishment:
Harman et al. (1996) - has established in Canterbury.
Hill et al. (2000) - establishment of A. umbellana is not yet certain; it has established only sporadically and at low densities.
Landcare Research (2006c) - Agonopterix umbellana were initially difficult to find even though pheromone trapping suggested the moths had established at 10 sites throughout the country. The first major outbreak was not seen until 2004, and the moth appears to be gaining strength in parts of the South Island while remaining rare in the North Island.
Gourlay (2011d) - now well established and common in parts of the South Island (especially Canterbury, Marlborough and Tasman) but still rare in the North Island.
Landcare Research (2017g) - well established and spreading at a site in Northland.
Impacts on target:
Gourlay (2011d) - where outbreaks have occurred the damage has been noticeable, but the overall effect on plant growth is unknown.
Landcare Research (2017g) - some impressive outbreaks in the South Island, but impact still unknown.
Paynter et al. (2018) - abundant, but impacts on the target plant are unknown and appear to be minor.
Paynter (2024) - factors influencing the success of weed biocontrol agents released and established in New Zealand were investigated. Each agent’s impact on the target weed in New Zealand was assessed as ‘heavy’, ‘medium’, ‘variable’, ‘slight’ or ‘none’, where a ‘heavy’, ‘medium’ or ‘variable’ impact have all been observed to reduce populations or percentage cover of their target weed in all or part of their respective target weed ranges in New Zealand. Results showed that: (i) agents that are highly damaging in their native range were almost invariably highly damaging in New Zealand; (ii) invertebrate agents with a closely related ‘native analogue’ species are susceptible to parasitism by the parasitoids that attack their native analogues and failed to have an impact on the target weed, and (iii) agent feeding guild helped predict agent impact - in particular, agents that only attack reproductive parts of the plant (e.g., seed and flower-feeders) are unlikely to reduce weed populations. Damaging impacts of A. umbellana, a defoliating moth, have not been reported in its native range (although it is heavily parasitised in Europe and it was thought it may achieve higher densities in New Zealand), it does not have a New Zealand native ecological analogue and its impact in New Zealand is assessed as ‘slight’.
Impacts on non-targets:
Cameron et al. (1989) - in laboratory tests in New Zealand, five of 63 tested plants, all closely related to gorse, appeared to be possible alternative hosts for A. umbellana. Four were not of any environmental or economic importance in New Zealand, but one, Cytisus proliferus (tagasaste) may become an important forage shrub in New Zealand in the future.
Landcare Research (2006b) - surveillance this year supports the prediction from host-testing that A. umbellana would not attack non-target species in the field.
Gourlay (2011d) - extremely unlikely it will attack plants other than gorse in New Zealand. In Europe it attacks other Ulex species that are not present in New Zealand.
Paynter et al. (2015) - surveys of potential non-target hosts Cytisus scoparius (Scotch broom), Trifolium pretense (red clover), Lupinus arboreus (tree lupin), Cytisus proliferus (tree lucerne, tagasaste) and Spartium junceum (Spanish broom) report no feeding.
References
Cameron PJ, Hill RL, Bain J, Thomas WP (1989). A Review of Biological Control of Invertebrate Pests and Weeds in New Zealand 1874-1987. Technical Communication No 10. CAB International Institute of Biological Control. DSIR Entomology Division. 424p.
Gourlay H (2011d). Gorse soft shoot moth: Agonopterix umbellana. The Biological Control of Weeds Book - Te Whakapau Taru: A New Zealand Guide (Landcare Research) [Updated 2020] https://www.landcareresearch.co.nz/discover-our-research/biodiversity-biosecurity/weed-biocontrol/projects-agents/biocontrol-agents/gorse-soft-shoot-moth/
Harman HM, Syrett P, Hill RL, Jessep CT. (1996). Arthropod introductions for biological control of weeds in New Zealand, 1929 - 1995. New Zealand Entomologist, 19(1): 71-80
Hill RL, Gourlay AH, Fowler SV (2000). The biological control program against gorse in New Zealand. In Proceedings of the X international Symposium on Biological Control of Weeds 2000 Jul (Vol. 917, pp. 909-917). Montana State University Bozeman, Montana, USA. https://www.landcareresearch.co.nz/assets/researchpubs/biologial_control_gorse_Hill_2000.pdf
Landcare Research (2006b). Are they behaving themselves? What’s New In Biological Control of Weeds? Annual Review. August 2006, 37: 6-7 https://www.landcareresearch.co.nz/assets/Publications/Weed-biocontrol/wtsnew37.pdf
Landcare Research (2006c). Our gaggle of gorse agents. What’s New In Biological Control of Weeds? May 2006, 36: 6-7 https://www.landcareresearch.co.nz/assets/Publications/Weed-biocontrol/wtsnew36.pdf
Landcare Research (2007a). New Zealand Arthropod Collection (NZAC) Biological Control Voucher Collection. Landcare Research website [Updated 2020] https://www.landcareresearch.co.nz/tools-and-resources/collections/new-zealand-arthropod-collection-nzac/databases-and-holdings/new-t2-landing-page/
Landcare Research (2017g). Who's who in biological control of weeds? Weed Biocontrol: What's New? 81: 10-11 https://www.landcareresearch.co.nz/publications/newsletters/biological-control-of-weeds/issue-81
Paynter Q (2024). Prioritizing candidate agents for the biological control of weeds. Biological Control, Volume 188, January 2024, Article Number 105396 https://doi.org/10.1016/j.biocontrol.2023.105396
Paynter Q, Fowler SV, Groenteman R. (2018). Making weed biological control predictable, safer and more effective: perspectives from New Zealand. BioControl 63: 427–436 (first published online 8 Aug 2017) https://doi.org/10.1007/s10526-017-9837-5 https://link.springer.com/article/10.1007/s10526-017-9837-5
Paynter QE, Fowler SV, Gourlay AH, Peterson PG, Smith LA and Winks CJ (2015). Relative performance on test and target plants in laboratory tests predicts the risk of non-target attack in the field for arthropod weed biocontrol agents. Biological Control 80: 133-142 https://doi.org/10.1016/j.biocontrol.2014.10.007
