Flower thrips are considered key pests in southern highbush (Vaccinium corymbosum L. x V. darrowi Camp) and rabbiteye (Vaccinium ashei Reade) blueberry fields in Florida. During 2005 and 2006, we evaluated the effectiveness of selected natural enemies (preventative and curative releases) for control of flower thrips in blueberries. Experimental designs were randomized complete blocks with 4 treatments and 4 replicates in 2005 and 3 treatments and 4 replicates in 2006. In 2005, treatments were evaluated as a preventative tactic and included the following biological control agents: (1) Thripor-I [Orius insidiosus Say (Hemiptera: Anthocoridae)], (2) Thripex-plus [Amblyseius cucumeris (Oudemans) (Acari: Phytoseiidae)], (3) combination of both O. insidiosus and A. cucumeris in 50% of standard dosages, and (4) untreated control (no natural enemies). Orius. insidiosus (Thripor-I) was released at 0.5 insects per m(2) and A. cucumeris (Thripex-Plus) at 0.5 sachets of 1000 mites per m(2). For the combination treatment, 50% of each standard dosage was released. In 2006, treatments were evaluated as a curative technique and included (1) Thripor-I (O. insidiosus) released at 10 insects per m(2), (2) Thripex-Plus, and (3) control [no natural enemies were released]. In 2005, the results indicated that thrips populations in the control were on average significantly lower than in treatments of O. insidiosus and A. cucumeris alone, implicating the potential for intraguild predation among natural enemies. In 2006, there were no significant differences among the treatments evaluated probably due to the short duration of time during which flower thrips are present in blueberry fields.
