Here we go again! In the past 5 years, Florida has been invaded by four new whitefly species. While these pests are causing damage mainly in landscapes, they can affect nursery production as well.
Last December Extension Director Steven Brown discovered Bondar’s Nesting Whitefly, Paraleyrodes bondar, in Lee County. Lab analysis confirmed that the species, native to Brazil, was different than the three other species of this genus already present in Florida. FDACS-DPI inspectors in South Florida report that Bondar’s Nesting Whitefly is sporadically present at high levels on Ficus benjamina plants. But unlike the Ficus Whitefly, Singhiella simplex, introduced in 2007, this new one is known to attack numerous other hosts including several palm species, hibiscus, guava and citrus. Infested leaves become coated with black sooty mold, and strands of white wax accumulate as the pupae mature. Both the upper and lower surfaces of the leaf can be infested, which is unusual for whiteflies.
A related species, the Rugose Spiraling Whitefly, Aleurodicus rugioperculatus, also has a wide host range. It was first spotted in 2009 in Miami-Dade County and later as far north as Polk County. Look for adults that are three times larger than more familiar whiteflies and eggs laid in a spiral. Juveniles produce so much honeydew and white waxy flocculant that leaves may become completely obscured.
Discovered in Florida in 2010, the ash whitefly, Siphoninus phillyreae, is a pest of numerous ornamental and fruit crops, including citrus. Heavy infestations cause leaf wilt, early leaf drop, and smaller fruit.
Control methods include scouting and careful monitoring, especially for plants brought in from South Florida. UF Entomologist Dr. Catherine Mannion notes that natural enemies such as Encarsia wasps, predatory beetles, and lacewings are the first line of defense. While insecticides may be warranted in severe cases, they should not be relied upon exclusively due to resistance issues and effects on non-target organisms.
Some useful links for these pests and more:
Florida Department of Agriculture and Consumer Services – Pest Alerts http://www.freshfromflorida.com/pi/pest-alerts ,
UF Tropical Research and Education Center – Ornamental Entomology http://trec.ifas.ufl.edu/mannion/pests.shtml
UF/IFAS Extension Electronic Data Information Source – Entomology and Nematology http://edis.ifas.ufl.edu/departments/entomology.html.