Phone calls and emails from residents to Village staff raised the possibility of an infestation of the rugose spiraling whitefly (aleurodicus rugioperclatus). On November 6, 2018, University of Florida scientists and staff (UF) conducted site visits to areas of suspected infestation and confirmed that whitefly numbers are on the increase. UF collected samples from coconut palms and gumbo limbo trees observed to have the infestations.
Typical signs of whitefly presence are as follows. Whitefly excretions are clear and sticky and provide a base for the growth of dark sooty mold. A white, fluffy, wax-like substance can also accumulate under leaves and fronds. "Old" whitefly deposits often appear as dust-like clouds when the host plant is shaken and showed UF that whitefly populations have been increasing for some time. UF also identified predatory beetles and wasp parasitoids, known natural enemies of the whitefly, in the samples.
Analysis of the November site visit results indicate that whitefly populations are starting to grow again in the Village after several years of low populations. This drop in whitefly presence also reduced the populations of natural enemies. The numbers of natural enemies are lagging behind the growth of whiteflies.
The whitefly population is expected to dissipate to some extent with cooler winter temperatures/ Observations in the field by Village staff in January 2019 suggest this is the case.
UF teams will return to the Key in the spring to re-assess whitefly populations. The Village and UF are taking the following steps to control whitefly on the most heavily infested palms and trees.
- All coconut palms in the public right-of-way are routinely trimmed in January and July (nuts and old fronds). In 2019 any whitefly-infested palm fronds will be removed. Infested fronds will be transported in a covered truck to minimize spreading the pest.
- UF is currently growing natural parasitoids (whitefly enemies) in their Homestead laboratory and will release them to infested trees in the Spring.
- The Village may resort to using insecticide as a last option.
Staff and UF experts will host a public meeting to educate the community once schedules allow. In the meantime, residents and/or their gardeners can follow these suggestions to help control whitefly in their properties.
- Monitor trees and palms for whiteflies.
- Ensure that infested fronds, branches or leaves are placed in sealed bags after removal from palms or trees.
- Notify the Village if heavy infestations are present. Call the Public Works Department Office at (305) 365-8945.