Abstract
The royal palm [Roystonia regia (Kunth) O.F. Cook] is a majestic and prized palm tree in South Florida landscapes and has relatively few pests. However, sudden population flare-ups of the royal palm bug (RPB) [Xylastodoris luteolus Barber (Hemiptera: Thaumastocoridae)] can be severely damaging. Damage appears as tan-gray, ragged new growth that reduces aesthetics and may affect photosynthetic ability. This study was conducted to evaluate the efficacy of soil-applied neonicotinoid systemic insecticides. All three active ingredients were tested at 0.05 oz a.i. (1.4 g) per inch trunk diameter. All of the treatments tested: Merit 2F (imidacloprid), Safari 2G and Safari 20 SG (dinotefuran), and Arena 50 WDG (clothianidin) provided excellent RPB control at 30 and 75 days after treatment. ELISA analysis of palm foliage showed dinotefuran translocated fastest, followed by imidacloprid then clothianidin. Compared to high-pressure foliar spraying, soil application of systemic insecticides is preferred in urban landscapes because the drift risk is eliminated. This is especially apt when treating tall palms with small canopy areas (in relation to hardwood tree canopies). High-visibility, specimen royal palms used to be treated preventively due to a presumed, long translocation period of imidacloprid. Now palms can be effectively treated curatively, since translocation occurs within 30 days.
