Mineral oil foliar applications in combination with insecticides affect tomato potato psyllid (Bactericera cockerelli) and beneficial insects in potato crops

ABSTRACTTomato potato psyllid (TPP), Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a vector for Candidatus Liberibacter solanacearum (Lso), a phloem-limited bacterium that causes severe production problems within the New Zealand potato industry. Field trials were conducted over three consecutive growing seasons between 2013 and 2016 at Pukekohe, New Zealand to determine the efficacy of an isoparaffinic petroleum distilled oil (JMS Stylet Oil®), applied as a foliar treatment within an insecticide programme, to control TPP. The effects of treatments on potato yield, tuber dry matter content and the incidence of zebra chip (ZC) in fried potato crisps were also assessed. This research demonstrated that JMS Stylet Oil, when used in combination with insecticides, achieved fewer insecticide applications, leading to reduced numbers of TPP nymphs and eggs on potato foliage, and lower incidence of ZC in deep-fried tuber crisps than weekly insecticide sprays, without adversely affecting plant growth and c...