부산대학교 도서관

Simple Summary: The southern red mite (SRM), Oligonychus ilicis is an emerging pest of southern highbush blueberries in Florida and Georgia causing significant yield and plant losses. The level of growers' familiarity and awareness regarding this mite pest was evaluated in 2020 to evaluate miticides and contribute to miticide registrations. Growers showed confidence in identifying this pest mite but less confidence in identifying the injury caused by their feeding. Additionally, few miticide options were reported as being used by the growers, demonstrating a need for more miticidal tools and more educational material to show the availability of other effective miticides in the market. Thus, the performance of registered and non-registered miticides was assessed based on the survival of SRM and naturally occurring predatory mites. The miticides that performed the best at suppressing this pest were fenpyroximate and fenazaquin, followed by acequinocyl, bifenazate used at a high rate, and spiromesifen. Sulfur-based miticides were not effective at suppressing SRM and maintained SRM numbers comparable to the control. Demonstrating the efficacy of miticides against SRM will allow growers to diversify their pesticidal toolbox and build more diverse and effective miticide rotations that keep their blueberry plantings safe while maintaining the lifespan of the chemical products. Tetranychid outbreaks have been detected since 2016 in southern highbush blueberries (SHB); however, it was not until 2019 that the southern red mite (SRM), Oligonychus ilicis (Acari: Tetranychidae) was confirmed as the pest causing severe bronzing and stunting, in multiple Florida and Georgia commercial blueberry plantings. To date, only three miticides (fenazaquin, fenpyroximate, and acequinocyl) have been registered for use in SHB and there are no clear guidelines on how to manage SRM in SHB. Similarly, there is no knowledge regarding the existence of natural enemies of SRM in SHB. This is the first report of naturally occurring predatory mites (Amblyseius sp. and Neoseiulus ilicis) associated with SRM in SHB. Predatory mites were recorded in blueberry bushes after treatment with seven miticides used to suppress SRM populations including spiromesifen, acequinocyl, sulfur, sulfur + molasses, bifenazate, fenpyroximate, and fenazaquin. The number of SRM recorded per leaf and averaged plant damage ratings (0 = no bronzing–4 = 100% bronzing) were used to evaluate miticide efficacy. Additionally, the presence or absence of predatory mites per sample was recorded. Fenpyroximate used as the standard miticide, significantly reduced mite numbers seven days after application, as well as acequinocyl and fenazaquin. Fenpyroximate and fenazaquin demonstrated the best performance for managing O. ilicis on SHB and treated bushes demonstrated significantly less bronzing compared with the control plants. These miticides were also safe to naturally occurring predatory mites. Lastly, the level of growers' awareness regarding SRM was assessed using surveys in 2020 to design adequate educational materials available to the grower community. [ABSTRACT FROM AUTHOR]