Potential of UV-C for management of two-spotted spider mites and thrips in Florida strawberry.

BACKGROUND: Major pests of Florida strawberry (two-spotted spider mites, Tetranychus urticae Koch; chilli thrips, Scirtothrips dorsalis Hood; and western flower thrips, Frankliniella occidentalis Pergande) are difficult to manage using only conventional chemical control. Previous research has demonstrated high mortality of T. urticae eggs after exposure to ultraviolet B (UV-B) light. Additionally, ultraviolet C (UV-C) light has been shown to suppress powdery mildew in strawberry at doses between 85 and 200 J m-2 with no damage to the plant. Therefore, UV-C may also have the potential to be used as an integrated pest management tool for arthropod pests of strawberry. The objectives of this study were to: (i) determine the effect of UV-C on T. urticae, S. dorsalis, and F. occidentalis natural populations in open-field strawberry; and (ii) determine the effect of UV-C on T. urticae egg hatch after application in open-field strawberry. Field studies were conducted during the 2019-2020 and 2020-2021 strawberry seasons in Florida, USA. Four treatments were compared: (i) foliar application of spinetoram in response to natural pest pressure; (ii) application of UV-C 200 J m-2 twice a week; (iii) application of UV-C 350 J m-2 twice a week; and (iv) a non-treated control. RESULTS: In the field trials, suppression of T. urticae was observed at 350 J m-2 in 2020-2021. In the other field trials, no effect was observed due to low natural infestations. No negative impact on yield was observed from UV-C applications. CONCLUSION: UV-C shows promise as a component of an integrated pest management program for T. urticae in strawberry. © 2022 Society of Chemical Industry.

Arthropod Pest Management in Strawberry.

The strawberry crop endures economic losses due to feeding injury from a number of phytophagous arthropod pests. A number of invasive pests have posed challenges to crop protection techniques in the strawberry cropping system recently. It is increasingly evident that sole reliance on chemical control options is not sustainable. In this review, current challenges and advances in integrated pest management of various strawberry pests are presented. Key pests discussed include thrips, mites, lygus bug, spotted wing drosophila, seed bug, weevils, aphids, whiteflies, and armyworms. Several integrated pest management techniques that include use of intercropping, resistant cultivars, irradiation with gamma rays, use of spectral sensitivity of pests, biological control agents and natural enemies, and biorational pesticides have recently been reported to be useful in managing the various strawberry pests. With the increase in world production of strawberry, several techniques will be necessary to manage the pest complex of strawberry.