Potential of the mirid bug, Engytatus nicotianae, for the biological control of the tomato-potato psyllid in greenhouses

The tomato-potato psyllid (TPP), Bactericera cockerelli, is a serious pest of solanaceous crops. As an alternative to the use of insecticides, we tested the potential of the mirid bug Engytatus nicotianae (adults) as a biocontrol agent of TPP on greenhouse tomato plants. The experiment comprised: a) a laboratory choice feeding assay to investigate the preferences of E. nicotianae when offered TPP eggs and nymphs and b) a greenhouse experiment to assess the potential of E. nicotianae as a biocontrol agent under close to commercial conditions. The laboratory choice experiment highlighted a preference by E. nicotianae for the first two TPP instars, followed by the third instar and then the eggs. Consumption of fourth instars occurred only when all other life-stages had been consumed. In the cage experiment, the E. nicotianae-only treatment produced the same numbers of fruits and flowers as the control (no insects), even though TPP feeds on tomato leaves and stems. In contrast, the TPP-only treatment resulted in fewer fruits and flowers. The simultaneous introduction of E. nicotianae and TPP markedly reduced TPP build up compared to the TPP-only treatment and prevented the pest from establishing at all in four of the seven replicates of the experiment. These findings suggest that E. nicotianae should be considered as a potential biocontrol tool against TPP and further research is needed to determine an optimum release configuration.