Biocontrol introduction
Target pest: Cytisus scoparius (Fabales: Fabaceae), Scotch broom, broom
Agent introduced: Leucoptera spartifoliella (Lepidoptera: Lyonetiidae), broom twig miner
Import source:
Gourlay (2009) - Leucoptera spartifoliella is native to Europe.
Import notes:
Harman et al. (1996), Gourlay (2009), Landcare Research (2014c) - accidental introduction.
Released:
Harman et al. (1996) - first recorded in New Zealand in 1950.
Establishment:
Harman et al. (1996) - is common on broom in New Zealand.
Gourlay (2009), Landcare Research (2014c) - now commonly found throughout New Zealand.
Impacts on target:
Harman et al. (1996) - kills broom twigs, causing considerable damage to the broom bushes.
Gourlay (2009) - some large outbreaks have caused severe damage to broom infestations.
Landcare Research (2014c) - often causes obvious damage.
Gourlay (2021) (accessed 2 Aug 2023) - a recent study at Hanmer Springs in the South Island showed that C. scoparius bushes infested with L. spartifoliella grew significantly less (3 cm) over a 2-month period than bushes that had been treated with insecticide to remove the twig miner (15 cm).
Impacts on non-targets:
Gourlay (2021a) - Leucoptera spartifoliella will only damage Cytisus scoparius (Scotch broom). Even other species of broom are not attacked.
References
Gourlay H (2021a). Broom twig miner: Leucoptera spartifoliella. The Biological Control of Weeds Book - Te Whakapau Taru: A New Zealand Guide (Landcare Research) https://www.landcareresearch.co.nz/discover-our-research/biodiversity-biosecurity/weed-biocontrol/projects-agents/biocontrol-agents/broom-twig-miner/
Gourlay H. (2009). The biological control of broom (Cytisus scoparius). IUFRO International Forest Biosecurity Conference, 16-20 March 2009, Rotorua, New Zealand. Popular Summaries. Compiled by Richardson M, Hodgson C and Forbes A. New Zealand Forest Research Institute Limited. 230-232
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
Landcare Research (2014c). Who's who in biocontrol of weeds? What's new in biological control of weeds? 69: 10-11 https://www.landcareresearch.co.nz/assets/Publications/Weed-biocontrol/WhatsNew69.pdf
