Potato psyllid detection with DNA barcoding

zebra chip disease

The potato psyllid (Bactericera cockerelli) is a hemipteran native to southern North America. It can significantly impact crop production, attacking a range of plants in the Solanaceae family including potato, tomato, eggplant, capsicum and chilli. The psyllid can also carry the bacterium Candidatus Liberibacter solanacearum, causing the ‘zebra chip’ disease in potato. The latter is a recently diagnosed disease of potatoes that causes discolouration of tubers which often becomes more clear during frying of potato chips. This disease causes very significant losses to potato farmers specializing on growth of tubers for chips or fries.

Bactericera cockerelli has been reported from Central America and New Zealand and has caused significant loss in potato yields during periods of major population increase. Maximum potato yield loss appears to be related to infestations occurring early in the growing season, or on crops with a significant leaf canopy by summer. The psyllids are not heat tolerant and it is thought they survive summer temperatures in crops with sufficient leaf canopy through summer to offer shade.

The Department of Agriculture and Food, Western Australia is currently undertaking surveillance in commercial crops and backyard gardens in the Perth area, following the suspect detection of potato psyllid in a commercial property north of the city and a couple of backyards. As this would be a first for Australia, authorities have been very vigilant in their reaction. The impacted properties have been quarantined and the movement of host material from these properties has been restricted. They also started DNA barcoding analysis to determine the exact species of the pest. The results are expected this week. Great to see that barcoding becomes state-of-the-art for such regulatory actions.