Post release monitoring of the parasitoid Tamarixia triozae against Bactericera cockerelli in New Zealand
Bactericera cockerelli (Hemiptera: Triozidae - EPPO A1 List), a vector of ‘Candidatus Liberibacter solanacearum’, was first reported in New Zealand in 2006 and has since caused significant economic damage. Following host specificity testing of the solitary ectoparasitoid Tamarixia triozae (Hymenoptera: Eulophidae), the parasitoid was released as a classical biological control agent in more than 30 sites in New Zealand in 2016. Post-release monitoring surveys to determine if the parasitoid had survived at release sites were conducted in Hawke’s Bay and Canterbury over two summer periods. B. cockerelli parasitized nymphs were found at 24 sites surveyed within a 25 km radius of known release sites in Hawke’s Bay. In Canterbury, the parasitoid was found up to 0.6 km from a known release site. Parasitism rates of approximately 16 % were recorded at release sites. T. triozae also feeds on psyllid nymphs so its establishment may lead to reducing the likelihood of B. cockerelli populations reaching damaging levels, or delaying this event. Further long-term monitoring is needed to determine the consequences of importing T. triozae on populations of B. cockerelli.
Sources
Davidson M, Sachtleben T, MacDonald F, Watkins L, Barnes AM, Drayton G, Walker M (2023) The establishment and spread of Tamarixia triozae, a parasitoid of the potato psyllid, in New Zealand. BioControl 68, 363-373. https://doi.org/10.1007/s10526-023-10194-6