Early predator catches the prey: pre-establishment of generalist predatory mites in greenhouse crops

Abstract: There is an increasing body of evidence demonstrating that biological control usinggeneralist predators can be a successful strategy. A major benefit of generalist predators is theirpossibility to establish in a crop before pest food is available. In the present study, we comparedthe pre-establishment potential of the phytoseiid predatory mites Amblyseius swirskii (Athias-Henriot), Transeius montdorensis (Schicha) and Amblydromalus limonicus (Garman andMcGregor) using pollen supplementation (NutrimiteTM) on a sweet pepper crop beforeflowering. For all three predatory mite species, significantly higher numbers were found ascompared to a control treatment without food addition. Next, we compared the potential to limitspider mite (Tetranychus urticae Koch) and western flower thrips (Frankliniella occidentalisPergande) outbreaks in the same preventative set-up using food supplementation. Additionally,we observed that besides predation on first instar larvae, the tested predatory mite species werecapable of detected and consuming thrips eggs embedded in the leaf tissue. The implications ofthe current findings will be discussed in the light of applicability in a commercial sweet pepper.