Seasonality of Bactericera cockerelli in potatoes (Solanum tuberosum) in South Auckland, New Zealand

Abstract The seasonality of Bactericera cockerelli, potato/tomato psyllid (PTP), a recently arrived pest of potatoes (Solanum tuberosum) and other Solanum spp., was investigated in South Auckland, New Zealand. Yellow sticky traps showed that adult PTP activity began in October mainly in volunteer potatoes and remained below c. 2/trap per week until mid December. Over this period, plant sampling was less sensitive than sticky traps. Potato crops harvested before c. 20 December showed satisfactory yield and quality. Trap catches in potatoes increased in late December and exceeded 100/trap per week in February in 2008 and 2009. The presence of nymphs in plant samples was positively correlated with these increases and associated with unacceptable levels of “zebra chip” disease and the presence of Liberibacter. Late planting of crops delayed the build up of PTP populations by c. 1 month, but nymphal populations still exceeded 1/leaf and damaged late crops. Yellow sticky traps provided an indication of when dam...