Vol. 127 (2014): Proceedings of the Florida State Horticultural Society
Ornamental, Garden & Landscape

Gumbo-limbo trees struggle with three new dieback plagues: puzzling witches’-broom symptoms, croton scale, and rugose spiraling whitefly

Douglas L. Caldwell
UF/IFAS
Aaron J. Palmateer
UF/IFAS
2014 Proceedings Florida State Horticultural Society Volume 127

Published 2018-03-15

Abstract

In 2013, gumbo limbo trees, Bursera simaruba (L.) Sarg., in south Florida were under siege with three dieback plagues: a witches’-broom symptom or rosette-type symptom of the terminal buds and two new, aggressive insect pests, the croton scale (Phalacrococcus howertoni Hodges & Hodgson) and the rugose spiraling whitefly (Aleurodicus rugioperculatus Martin). Samples from 16 trees exhibiting witches’-broom were tested for phytoplasma infection. A phytoplasma infection matching a ‘Candidatus phytoplasma asteris’-related stain, previously classified as a subgroup 16SrI-B member, was reliably detected in only one tree thus ruling out phytoplasmas as the primary cause of this symptom. Other fungal pathogens are discussed.