Florida is the second largest producer of strawberries in the United States. However, the production system faces numerous challenges, especially Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) infestations. Management of this pest involves applying insecticides and use of predatory mites, particularly Amblyseius swirskii Athias-Henriot, Neoseiulus cucumeris Oudemans, and Neoseiulus californicus McGregor (Mesostigmata: Phytoseiidae). Strawberry growers in Florida are concerned about the compatibility of the commercial formulations of insecticides used in strawberry pest management with predatory mites. This study assessed the residual effect of commercial insecticides used in strawberry production on the survival, feeding, and oviposition of the 3 predators. Using Munger cells, predators were exposed to commercial formulations of spinetoram, cyantraniliprole, azadirachtin + pyrethrin, Beauveria bassiana, Cordyceps javanica, capsicum, garlic, and canola oil extracts, and water control. There was a gradual decline in the survival and feeding of predatory mites when exposed to all insecticides. Spinetoram had the highest impact on the survival and feeding of all predators compared to other insecticides, while C. javanica had the lowest impact. Cyantraniliprole and azadirachtin + pyrethrin significantly reduced predator survival after 72 h of exposure, whereas capsicum, garlic, and canola oil extracts caused a similar reduction after 96 h. All predators consumed low proportions of S. dorsalis across all treatments. Oviposition was low in all treatments, with no discernable variation among treatments. These results highlight the potential of using entomopathogenic fungi in conjunction with A. swirskii, N. cucumeris, and N. californicus for the management of S. dorsalis and T. urticae in strawberries.

Florida’s strawberry industry is currently valued at $511 million annually but faces challenges from pathogens and arthropod pests especially Tetranychus urticae Koch (twospotted spider mite) and Scirtothrips dorsalis Hood (chilli thrips). Predatory mites, particularly Neoseiulus cucumeris Oudemans, Neoseiulus californicus McGregor, and Amblyseius swirskii Athias-Henriot, play a crucial role in pest management. However, there are concerns regarding how these biological control agents are affected by fungicides used in current pathogen management strategies. This study assessed the residual effects of commonly used fungicides in strawberries on the survival, feeding, and oviposition of these predatory mites. Commercially sourced predatory mites were reared on S. dorsalis larvae, and gravid female predators placed on fungicide treated strawberry leaf discs in a Munger cell for 120 h. Fungicides tested included two formulations of Captan, hydrogen peroxide + peroxyacetic acid, cyprodinil + fludioxonil, tetramethylthiuram disulfide, cyflufenamid and a control. All fungicides tested had an impact on the survival, feeding, and oviposition of the predators. Among the fungicide treatments, the lowest predator survival was observed in the cyprodinil + fludioxonil treatment, while the highest was observed in the hydrogen peroxide + peroxyacetic acid and tetramethylthiuram disulfide treatments. In all treatments, feeding and oviposition greatly varied among predators; specifically, N. cucumeris and A. swirskii had the lowest prey consumption, while N. californicus had the highest. These findings highlight the potential incompatibility between fungicides and predatory mites and demonstrate the need for the development of a fungicide rotation program tailored to the different susceptibilities of predators to fungicides.

Since 2015, Scirtothrips dorsalis Hood has emerged as the main pest of strawberries in Florida. Given the limited management options, there is a recognized need to expand on the management strategies for this pest. Therefore, we explored the possibility of using banker plants to recruit naturally occurring predators of thrips into strawberry fields to suppress S. dorsalis. The study began in the 2021–2022 strawberry season where five banker plants were screened to determine which ones could consistently attract thrips predators by flowering throughout the strawberry season. Capsicum annum L. (ornamental pepper) and Lobularia maritima L. (sweet alyssum) were selected for further evaluation. In the 2022–2023 strawberry season, using a randomized complete block design we assessed the capability of these banker plants to attract thrips predators into the strawberry field. In addition, we examined how the banker plant distance from the strawberry plants influenced the S. dorsalis pest suppression. Our results showed that strawberries located within 3.7 m of ornamental pepper plants had less leaf damage from S. dorsalis compared with those farther away, which may result from the repellent effect of the ornamental peppers. Additionally, Geocoris spp. and Orius spp. were identified as the main thrips predators in the system, although in relatively low numbers. Therefore, these results highlight the potential of incorporating ornamental pepper as a banker plant in strawberry production. Additional applications of this research are explored below.

In Florida, strawberries are prone to infestation by Tetranychus urticae Koch (twospotted spider mite; Trombidiformes: Tetranychidae) and Scirtothrips dorsalis Hood (chilli thrips; Thysanoptera: Thripidae). Management of these pests using conventional insecticides is becoming difficult, thereby forcing many growers to adopt the use of commercially available biological control agents including Neoseiulus cucumeris Oudemans and Amblyseius swirskii Athias-Henriot (both Mesostigmata: Phytoseiidae). These predators are mass reared on prey different from T. urticae, and their prey switching capacity is unknown. Therefore, the objective of this study was to compare the predation capacity of A. swirskii and N. cucumeris feeding on familiar and unfamiliar prey. Thus, using T. urticae as a non-familiar prey model organism, a no choice test was conducted where A. swirskii and N. cucumeris were each provided with Acarus spp. (commonly used as prey for commercial rearing of predatory mites) as familiar prey and eggs, deutonymphs, and adult females of T. urticae as unfamiliar prey. Prey consumption was recorded at 12, 24, 36 and 48 h. Our results show that both A. swirskii and N. cucumeris exhibited higher prey consumption when prey was familiar (Acarus spp.) compared to unfamiliar prey. Additionally, both predators showed higher consumption of eggs compared to T. urticae nymphs and adults. In 12 h, both predators had consumed 50 % of eggs, however, 36–48 h were required for 50 % of the T. urticae adults and nymphs to be consumed. Therefore, strawberry growers utilizing these predatory mites ought to refrain from the use of insecticides known to be detrimental to predatory mites for a period of at least 48 h to allow the predators to adjust to the new prey and environment.

This study examined the thrips (Thysanoptera: Thripidae) species complex associated with relay-cropped strawberry–Jalapeño pepper fields in Florida and evaluated how sampling methods influenced species detection. Four thrips species were present across all fields, with Frankliniella bispinosa Morgan being the most common, while Scirtothrips dorsalis Hood, Thrips palmi Karny, and Frankliniella occidentalis (Pergande) occurred at substantial levels. Whole-plant sampling provided the most accurate representation of thrips species composition and was essential for detecting less common species. S cirtothrips dorsalis appeared later in the season and their population increased toward the end of the Jalapeño pepper crop, suggesting that relay-cropped peppers may serve as a source of S. dorsalis for subsequent strawberry plantings.

The invasive Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is currently the most significant pest of strawberries in Florida. Managing this pest is challenging due to its low susceptibility to many commonly used insecticides. As an additional management strategy, we propose using flowering plants (banker plants) to attract naturally occurring predators of thrips, which can help suppress S. dorsalis populations in field strawberries.