Target pest: Cirsium arvense (Asterales: Asteraceae), Californian thistle
Agent introduced: Lema cyanella (Coleoptera: Chrysomelidae), Californian thistle leaf beetle
Cameron et al. (1989) - 100 adults were received from Regina Station of Agriculture Canada in June 1981, and reared for three generations in quarantine prior to release.
1983, early 1990's
Cameron et al. (1989) - one release from the 1981 importation was made in 1983 in a field cage at Winchmore (Mid Canterbury).
Hayes (2007b) - released widely throughout New Zealand from the 1990 importation.
Cameron et al. (1989) - the 1983 release did not establish. An extended period of artificial rearing (10 generations) in quarantine in Canada prior to importation, and another three generations and rephasing in quarantine in New Zealand prior to release probably destroyed all chances of environmental adaptation and eventual establishment.
Harman et al. (1996) - has established in Canterbury from the 1990s releases.
Hayes (2007a, 2007b) - the beetles are thought to have survived at one site only near Auckland from the releases in the 1990s, though numbers there remain low.
Cripps et al. (2011) - has established at just one site in northern New Zealand where it has only recently become common after remaining almost undetectably rare at this site for about 15 years.
Landcare Research (2017g) - only established at one site near Auckland from which it is dispersing.
Landcare Research (2019i) - possibly also established at one site in the Hawke's Bay.
Impacts on target:
Hayes (2007b) - can cause heavy damage when kept on caged plants, but in the field the level of damage appears inconsequential to the plant.
Landcare Research (2015i) - causes obvious damage at the one site (near Auckland) where it is established.
Impacts on non-targets:
Hayes (2007b) - extremely unlikely to attack plants other than Californian thistle, and possibly Scotch thistle (Cirsium vulgare), nodding thistle (Carduus nutans) and variegated thistle (Silybum marianum) to a lesser extent.
Cripps et al. (2011) - the host range of L. cyanella species is confined to species of Cirsium, Carduus and Silybum. New Zealand has no native plants in the tribe (Cardueae, commonly known as thistles) to which these genera belong.
Paynter et al. (2015) - surveys of potential non-target host Carduus nutans (nodding thistle) show this plant (an exotic weed) is a 'full' host (can support breeding populations).
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.
Cripps MG, Gassmann A, Fowler SV, BourdÃ´t GW, McClay AS, Edwards GR. (2011). Classical biological control of Cirsium arvense: Lessons from the past. Biological Control 57: 165â€“174
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
Hayes L (2007a). Status of weed biocontrol agents in Southland. A report prepared for Environment Southland Sept 2007. Landcare Research Contract Report: LC0708/022
Hayes L (2007b). Californian Thistle Leaf Beetle. In The Biological Control of weeds Book (Landcare Research) https://www.landcareresearch.co.nz/discover-our-research/biosecurity/weed-management/using-biocontrol/the-biological-control-of-weeds-book/
Landcare Research (2015i). Who's who in biological control of weeds? Weed Biocontrol: What's New? 73: 10-11 http://www.landcareresearch.co.nz/publications/newsletters/biological-control-of-weeds/issue-73
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
Landcare Research (2019i). Who's who in biological control of weeds? Weed Biocontrol: What's New? 89, August 2019 https://www.landcareresearch.co.nz/publications/newsletters/biological-control-of-weeds/weed-biocontrol-issue-89/whos-who-in-biological-control-of-weeds
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