Evaluation of a guardian plant system to suppress Frankliniella occidentalis (Thysanoptera: Thripidae) in greenhouse ornamentals

Abstract

BACKGROUNDWestern flower thrips (WFT), Franklinella occidentalis (Pergande), is an economically damaging pest of greenhouse ornamentals. A ‘guardian plant system’ (GPS) that targeted WFT was evaluated under controlled and commercial greenhouse conditions. This system used mycotized millet grains with the entomopathogenic fungus Beauveria bassiana (Balsamo‐Crivelli) Vuillemin applied to soil of potted marigolds, Tagetes patula (L.), combined with the foliar‐dwelling predatory mite Neoseiulus (=Amblyseius) cucumeris (Oudemans) in slow‐release sachets under controlled greenhouse conditions, and with the addition of a pheromone lure under commercial settings.RESULTSSignificantly fewer WFT and less foliar damage on GPS was observed over the 10 and 12 weeks experimental periods compared to the untreated controls. Predatory mites were maintained up to 10 weeks with one release under controlled greenhouse conditions and 12 weeks with two releases in commercial greenhouses. In commercial greenhouses, greater numbers of WFT were found on marigolds than on crop plants within 1 m of the system. Fungal granules persisted for 12 weeks up to 2.5 × 105 CFU g−1 in the GPS soil.CONCLUSIONThe use of biological control agents to suppress WFT within a GPS could be a useful IPM strategy for greenhouse production. The marigold GPS attracted WFT which were suppressed primarily through predation by foliar‐dwelling predatory mites and to a lesser extent, infection from conidia produced by the granular fungal formulation in the soil. Further investigations into system deployment and fungal granular application rates and new fungal formulations are suggested to improve system efficacy. © 2023 Society of Chemical Industry.

Effects of a Bank Plant on the Control of Rice Planthoppers: A Field Study

“…In addition, this strategy is more labor and cost-efficient than other biological control strategies [18,20]. Numerous studies have been conducted on bank plant systems, but most are focused on indoor or greenhouse conditions [11,21,22]. Large areas of field crops must account for additional influencing factors and feasibility, including variable and unstable environmental factors, compatibility of the bank plant system with the crop system, and benefits to farmers.…”

Effects of Ultraviolet-C Exposure on Western Flower Thrips, Frankliniella occidentalis, and Ornamental Plants

“…A rating system was developed to assess UV-C damage, which was modified from a method commonly used by the authors to assess foliar feeding damage by WFT [31]. The level of damage characteristic of UV-C damage (defoliation, discoloration, and leaf curling) on each plant was assessed visually (Figure 2) using the following criteria:…”