The tomato potato psyllid, Bactericera cockerelli (Šulc, 1909) (Hemiptera: Triozidae): a review of the threat of the psyllid to Australian solanaceous crop industries and surveillance for incursions in potato crops

The tomato potato psyllid, Bactericera cockerelli (Šulc, 1909), is a major biosecurity threat to Australian solanaceous crop industries. Native to North and Central America, B. cockerelli was accidentally introduced into New Zealand in the mid-2000s. The psyllid is a vector of a phloem-limited, alpha-proteobacterium, ‘Candidatus Liberibacter solanacearum’ (= ‘Ca. L. psyllaurous’), which is associated with psyllid yellows disease in tomatoes, potatoes, capsicums, eggplants and tamarillos, and zebra chip disease in potatoes. Both the vector and pathogen have had a devastating impact on the solanaceous crop industries they affect, resulting in millions of dollars of losses annually through increased pest control and surveillance, reduced yields and disruption to commodity export markets. In April 2014, B. cockerelli and ‘Ca. L. solanacearum’ were reported on Norfolk Island, and it is feared that they could enter other Australian States or Territories either through the accidental importation of infested plant material or by the dispersal of psyllids on easterly airflows from New Zealand. In this paper, we give an overview of the threat of the vector and pathogen to Australian commodities. We report on an ongoing surveillance program, initiated in February 2011, designed to detect incursions of B. cockerelli in eastern Australian potato fields using yellow sticky traps. During the last 3 years, over 2300 traps were placed in the major potato growing regions of Tasmania, Victoria, South Australia and Queensland. No B. cockerelli were detected but over 9600 other Psylloidea were trapped, mainly Ctenarytaina spp. and Acizzia spp. (Psyllidae). Only 0.3% of all Psylloidea caught belonged to the Triozidae allowing the rapid differentiation of the majority of trapped psyllids from B. cockerelli based on wing venation. Recommendations are made for further research and to extend the surveillance program to include other Australian solanaceous crop industries.