Target pest: Cytisus scoparius (Fabales: Fabaceae), Scotch broom, broom
Agent introduced: Arytainilla spartiophila (Hemiptera: Psyllidae), broom psyllid
Imported: 1991, 1992, 1994
Import source: UK
Release details: Gourlay (2010) - released throughout New Zealand in the mid-1990s.
Establishment: Gourlay (2009, 2010) - well established at sites throughout most of the country.
Impacts on target: Gourlay (2009, 2010) - high populations can cause severe damage to new growth; there have been a few outbreaks, especially in Southland but they are still not common. Performance may be affected by predation by mirid bugs (Sejanus spp.). Too early to assess impact. Paynter et al. (2017) - A. spartiophila is abundant with persistent outbreaks in some regions, but impacts on the target plant appear to be minor.
Impacts on non-targets: Gourlay (2010) - will only damage Scotch broom (Cytisus scoparius). Will not even attack other broom species such as Montpellier broom (Genista monspessulana) or white broom (Cytisus multiflorus).
Gourlay H (2010). Broom Psyllid. In The Biological Control of Weeds Book (Lancare Research) http://www.landcareresearch.co.nz/research/biocons/weeds/book/documents/Broom_psyllid.pdf
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
Landcare Research (2007). New Zealand Arthropod Collection (NZAC) Biological Control Voucher Collection. http://www.landcareresearch.co.nz/resources/collections/nzac/holdings/biological-control-voucher-collection
Paynter Q, Fowler SV, Groenteman R. (2017). Making weed biological control predictable, safer and more effective: perspectives from New Zealand. BioControl (First online: 8 Aug 2017). https://doi.org/10.1007/s10526-017-9837-5