Manatee Extension reports that this year might be especially bad for royal palm bugs (RPB) in South Florida. It reports that extension agents from Collier, Palm Beach, Miami Dade and Broward are reporting heavy RPB infestations. Dr. Doug Caldwell, Collier County Extension Agent and entomologist, says the outbreak is the worst he’s seen in 11 years.
The PRB is very small, reaching a length of only 2.5 mm (about 1/10th of an inch). Adults are pale yellow-green in color except for the red eyes. The Cuban royal palm, Roystonea regia, is the only known host, reports Manatee Extension.
The RPB is found primarily on newly opened leaflets, where its damage first appears as small yellow spots. Older leaflets with damage gradually develop brownish streaks. Eggs can be found among the membranous scales that cover the undersurface of the leaflet midrib.
Females usually deposit one egg per day, and eggs hatch in eight to nine days; full development ranges from 23 to 37 days.
More information is available on the UF/IFAS Featured Creatures website:http://ow.ly/aC8DB.
A study (http://ow.ly/aC92R), conducted by Drs. Doug Caldwell and Ali, 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.
Photo credits: Top photo – Dr. Lyle Buss, UF/IFAS, 2nd photo down – Dr. Doug Caldwell, Collier County Extension, 3rd photo down – Dr. F. W. Howard, UF/IFAS, Bottom photo – Dr. A. D. Ali, Davey Tree Expert Company.