Predation efficacy of commercially available Amblyseius swirskii Athias-Henriot (Mesostigmata: Phytoseiidae) on strawberry pest Tetranychus urticae Koch (Trombidiformes: Tetranychidae)

Monday, November 14, 2022

12:06 PM – 12:18 PM PT

Location: Vancouver Convention Centre, Meeting Room 217/218/219

Presenting Author(s)

Allan Busuulwa

Graduate Student
University of Florida
Wimauma, Florida

Co-Author(s)

Sriyanka Lahiri

Assistant Professor
University of Florida
Lithia, Florida

Florida is the second largest producer of strawberries (Fragaria x ananassa) particularly winter strawberries in the United States, with a total contribution of over $399 million dollars to a $2.23 billion dollar industry. Currently, the major economic pests of strawberries in Florida include phytophagous thrips particularly Scirtothrips dorsalis Hood, and spider mites especially Tetranychus urticae Koch. Growers rely on insecticides as a management strategy for these pests, an approach that has accelerated the development of insecticide resistance among pest populations. As a result, many growers are adopting the use of biological control agents, particularly the generalist predatory mite, Amblyseius swirskii Athias-Henriot to manage these pests. Nevertheless, the predatory efficacy of commercial A. swirskii with no previous exposure to T. urticae, for suppressing T. urticae in strawberries remains to be established. To determine the predatory efficacy, A. swirskii was purchased from commercial suppliers, starved for 48 hours and presented with five adult female T. urticae, fifty T. urticae eggs, ten T. urticae deutonymphs and five adult female, Acarus spp. (control). The total number of T. urticae adults, eggs, deutonymphs, and Acarus spp. consumed by A. swirskii were recorded at 12, 24, 36, and 48 hours and percentage mortality determined. Our results indicate that commercially available A. swirskii requires at least 48 h of exposure to various life stages of T. urticae in order to attain an efficacy of at least 80%.