Leaf anatomy and chemistry in ornamental Arecaceae species: possible barriers to Raoiella indica Hirst (Acari: Tenuipalpidae) feeding

Abstract

The red palm mite, Raoiella indica Hirst (Acari: Tenuipalpidae), has been reported on 91 host plant species in Neotropical
region. However, potential to feed on these plant species depends on anatomical and chemical characteristics, which can
influence mite development and reproduction. Thus, in this study anatomical features such as cuticle-epidermis width,
mesophyll depth and width, stomatal index and density; and also secondary metabolites (SM) concentration obtained
by thin layer chromatography were evaluated as potential barriers to mite feeding in 11 ornamental important Arecaceae
species Coccothrinax barbadensis (Lodd. ex Mart.) Becc., Cocos nucifera L, Mauritia flexuosa L. f., Roystonea oleracea
(Jacq.) O.F. Cook, Sabal mauritiiformis (Karsten) Griseb. & Wendl, Syagrus amara (Jacq.) Mart., S. coronata (Martius)
Becc., S. romanzoffiana (Cham.) Glassman, S. sancona H. Karsten, S. schizophylla (Mart.) Glassman and S. stenopetala
Burret. Although differences in cuticle and depth mesophyll were detected, these variables seem not to represent a feeding
barrier for R. indica feeding. Conversely, stomata disposition on leaf surface could make infra-capitulum and stylets easier
to penetrate and feed. More detailed studies on anatomy and chemical composition of Arecaceae and Zingiberales species
should be addressed to determine their effect on red palm mite´s development and reproduction.