Target pest: Ulex europaeus (Fabales: Fabaceae), gorse
Agent introduced: Sericothrips staphylinus (Thysanoptera: Thripidae), gorse thrips
Cornwall, England (1989), Portugal via Hawai'i (2001)
Gourlay (2007f) - the English strain imported in 1989 thought to be slow to disperse because winged forms not produced as commonly as non-winged. Consequently a Portuguese strain, thought to disperse more quickly, was imported in 2001.
Gourlay (2007f) - the English strain was widely released in the few years after its importation in 1989. The Portuguese strain was imported in 2001 and widely released in subsequent years.
Harman et al. (1996) - seems to be establishing readily throughout the country.
Rees & Hill (2001) - Sericothrips staphylinus is now established widely in New Zealand.
Gourlay (2007f) - the English strain established at sites throughout New Zealand but has been slow to disperse. The Portuguese strain has also established. The thrips are becoming increasingly common throughout New Zealand.
Impacts on target:
Rees & Hill (2001) - Sericothrips staphylinus produces large populations in culture, and commonly kill potted plants. Pot trials have demonstrated impacts on seedling growth even at low density but the long-term impact on gorse plants in the field is not yet known. It has not yet caused noticeable mortality of mature gorse plants in the field.
Gourlay (2007f) - the impacts of S. staphylinus are not yet known. While it can now be commonly found on gorse, it is less common to see gorse bushes that appear to be severely affected by them. However, studies in the UK and Australia found that S. staphylinus could reduce the growth and survival of seedlings, even when present in low numbers, and this may be where they have the greatest impact.
Paynter et al. (2018) - while S. staphylinus is abundant, impacts on the target plant are unknown but appear to be minor.
Lam et al. (2021) - laboratory trials investigating the functional responses of a predatory mite found on gorse in New Zealand, Amblyseius herbicolus, to first instar S. staphylinus larvae, indicate that A. herbicolus is likely to be a highly effective predator of S. staphylinus. These results indicate that the presence of A. herbicolus on gorse in New Zealand is a likely explanation for the failure of S. staphylinus as a weed biocontrol agent.
Impacts on non-targets:
Gourlay (2007f) - Sericothrips staphylinus will only damage gorse.
Paynter et al. (2015) - surveys of potential non-target host Cytisus proliferus (tree lucerne, tagasaste) report no feeding.
Gourlay H (2007f). Gorse Thrips: Sericothrips staphylinus. The Biological Control of Weeds Book - Te Whakapau Taru: A New Zealand Guide (Landcare Research) [Updated 2021] https://www.landcareresearch.co.nz/discover-our-research/biodiversity-biosecurity/weed-biocontrol/projects-agents/biocontrol-agents/gorse-thrips/
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
Lam W, Paynter Q, Zhang Z-Q. (2021). Functional response of Amblyseius herbicolus (Acari: Phytoseiidae) on Sericothrips staphylinus (Thysanoptera: Thripidae), an ineffective biocontrol agent of gorse. Biological Control 152, January 2021, art. no. 104468 (first published online Nov 2020) https://doi.org/10.1016/j.biocontrol.2020.104468
Paynter Q, Fowler SV, Groenteman R. (2018). Making weed biological control predictable, safer and more effective: perspectives from New Zealand. BioControl 63: 427â€“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