Zoophytophagous mirids provide pest controlby inducing direct defences, antixenosis andattraction to parasitoids in sweet pepper plants

Abstract

BACKGROUND: In addition to their services as predators, mirid predators are able to induce plant defences by phytophagy.However, whether this induction occurs in sweet pepper and whether it could be an additional benefit to their role as a biologicalcontrol agent in this crop remain unknown. Here, these questions were investigated in two model insects, the mirids Nesidiocoristenuis and Macrolophus pygmaeus.RESULTS: Plant feeding behaviour was observed in both N. tenuis and M. pygmaeus on sweet pepper and occupied 33% and14% of total time spent on the plant, respectively. The punctures caused by mirid plant feeding induced the release of a blend ofvolatile organic compounds (VOCs) which repelled the herbivore pests Frankliniella occidentalis and Bemisia tabaci and attractedthe whitefly parasitoid Encarsia formosa. The repellent effect on B. tabaci was observed for at least 7 days after initial exposureof the plant to N. tenuis, and attraction of E. formosa remained functional for 14 days.CONCLUSION: Plant defences induced by the feeding of mirid predators, their subsequent effec ts on the behaviour of bothpests and natural enemies, and the persistence of these observed effec t s open the door to new control strategies in the sweetpepper crop. Further application of this research is discussed, such as the vaccination of plants by zoophytophagous mirids inthe nursery before transplantation.